diff --git a/src/NimBLEAttValue.h b/src/NimBLEAttValue.h
index ba92b080..bddf020e 100644
--- a/src/NimBLEAttValue.h
+++ b/src/NimBLEAttValue.h
@@ -73,6 +73,14 @@ template <typename T>
 struct Has_c_str_length<T, decltype(void(std::declval<T&>().c_str())), decltype(void(std::declval<T&>().length()))>
     : std::true_type {};
 
+/* Used to determine if the type passed to a template has a value_type member (std::vector, std::array, std::string, etc.). */
+template <typename T, typename = void>
+struct Has_value_type : std::false_type {};
+
+template <typename T>
+struct Has_value_type<T, decltype(void(sizeof(typename T::value_type)))>
+    : std::true_type {};
+
 /**
  * @brief A specialized container class to hold BLE attribute values.
  * @details This class is designed to be more memory efficient than using\n
@@ -274,13 +282,32 @@ class NimBLEAttValue {
     /**
      * @brief Template to set value to the value of <type\>val.
      * @param [in] v The <type\>value to set.
-     * @details Only used if the <type\> has a `data()` and `size()` method.
+     * @details Only used if the <type\> has a `data()` and `size()` method with `value_type`.
+     * Correctly calculates byte size for containers with multi-byte element types.
+     */
+    template <typename T>
+#  ifdef _DOXYGEN_
+    bool
+#  else
+    typename std::enable_if<Has_data_size<T>::value && Has_value_type<T>::value, bool>::type
+#  endif
+    setValue(const T& v) {
+        return setValue(
+            reinterpret_cast<const uint8_t*>(v.data()),
+            v.size() * sizeof(typename T::value_type)
+        );
+    }
+
+    /**
+     * @brief Template to set value to the value of <type\>val.
+     * @param [in] v The <type\>value to set.
+     * @details Only used if the <type\> has a `data()` and `size()` method without `value_type`.
      */
     template <typename T>
 #  ifdef _DOXYGEN_
     bool
 #  else
-    typename std::enable_if<Has_data_size<T>::value, bool>::type
+    typename std::enable_if<Has_data_size<T>::value && !Has_value_type<T>::value, bool>::type
 #  endif
     setValue(const T& v) {
         return setValue(reinterpret_cast<const uint8_t*>(v.data()), v.size());
@@ -295,7 +322,11 @@ class NimBLEAttValue {
     template <typename T>
     typename std::enable_if<!std::is_pointer<T>::value, bool>::type setValue(const T& s) {
         if constexpr (Has_data_size<T>::value) {
-            return setValue(reinterpret_cast<const uint8_t*>(s.data()), s.size());
+            if constexpr (Has_value_type<T>::value) {
+                return setValue(reinterpret_cast<const uint8_t*>(s.data()), s.size() * sizeof(typename T::value_type));
+            } else {
+                return setValue(reinterpret_cast<const uint8_t*>(s.data()), s.size());
+            }
         } else if constexpr (Has_c_str_length<T>::value) {
             return setValue(reinterpret_cast<const uint8_t*>(s.c_str()), s.length());
         } else {
diff --git a/src/NimBLECharacteristic.h b/src/NimBLECharacteristic.h
index 789d21d7..58017907 100644
--- a/src/NimBLECharacteristic.h
+++ b/src/NimBLECharacteristic.h
@@ -112,15 +112,35 @@ class NimBLECharacteristic : public NimBLELocalValueAttribute {
     }
 
     /**
-     * @brief Template to send a notification with a value from a class that has a data() and size() method.
+         * @brief Template to send a notification with a value from a class that has a data() and size() method with value_type.
      * @param [in] v The value to send.
      * @param [in] connHandle Optional, a connection handle to send the notification to.
+     * @details Correctly calculates byte size for containers with multi-byte element types.
      */
     template <typename T>
 #  ifdef _DOXYGEN_
     bool
 #  else
-    typename std::enable_if<Has_data_size<T>::value, bool>::type
+    typename std::enable_if<Has_data_size<T>::value && Has_value_type<T>::value, bool>::type
+#  endif
+    notify(const T& v, uint16_t connHandle = BLE_HS_CONN_HANDLE_NONE) const {
+        return notify(
+            reinterpret_cast<const uint8_t*>(v.data()),
+            v.size() * sizeof(typename T::value_type),
+            connHandle
+        );
+    }
+
+    /**
+     * @brief Template to send a notification with a value from a class that has a data() and size() method without value_type.
+     * @param [in] v The value to send.
+     * @param [in] connHandle Optional, a connection handle to send the notification to.
+     */
+    template <typename T>
+#  ifdef _DOXYGEN_
+    bool
+#  else
+    typename std::enable_if<Has_data_size<T>::value && !Has_value_type<T>::value, bool>::type
 #  endif
     notify(const T& v, uint16_t connHandle = BLE_HS_CONN_HANDLE_NONE) const {
         return notify(reinterpret_cast<const uint8_t*>(v.data()), v.size(), connHandle);
@@ -160,7 +180,27 @@ class NimBLECharacteristic : public NimBLELocalValueAttribute {
     }
 
     /**
-     * @brief Template to send a indication with a value from a class that has a data() and size() method.
+     * @brief Template to send a indication with a value from a class that has a data() and size() method with value_type.
+     * @param [in] v The value to send.
+     * @param [in] connHandle Optional, a connection handle to send the notification to.
+     * @details Correctly calculates byte size for containers with multi-byte element types.
+     */
+    template <typename T>
+#  ifdef _DOXYGEN_
+    bool
+#  else
+    typename std::enable_if<Has_data_size<T>::value && Has_value_type<T>::value, bool>::type
+#  endif
+    indicate(const T& v, uint16_t connHandle = BLE_HS_CONN_HANDLE_NONE) const {
+        return indicate(
+            reinterpret_cast<const uint8_t*>(v.data()),
+            v.size() * sizeof(typename T::value_type),
+            connHandle
+        );
+    }
+
+    /**
+     * @brief Template to send a indication with a value from a class that has a data() and size() method without value_type.
      * @param [in] v The value to send.
      * @param [in] connHandle Optional, a connection handle to send the notification to.
      */
@@ -168,7 +208,7 @@ class NimBLECharacteristic : public NimBLELocalValueAttribute {
 #  ifdef _DOXYGEN_
     bool
 #  else
-    typename std::enable_if<Has_data_size<T>::value, bool>::type
+    typename std::enable_if<Has_data_size<T>::value && !Has_value_type<T>::value, bool>::type
 #  endif
     indicate(const T& v, uint16_t connHandle = BLE_HS_CONN_HANDLE_NONE) const {
         return indicate(reinterpret_cast<const uint8_t*>(v.data()), v.size(), connHandle);
@@ -190,7 +230,11 @@ class NimBLECharacteristic : public NimBLELocalValueAttribute {
     typename std::enable_if<!std::is_pointer<T>::value && !std::is_array<T>::value, bool>::type notify(
         const T& value, uint16_t connHandle = BLE_HS_CONN_HANDLE_NONE) const {
         if constexpr (Has_data_size<T>::value) {
-            return notify(reinterpret_cast<const uint8_t*>(value.data()), value.size(), connHandle);
+            if constexpr (Has_value_type<T>::value) {
+                return notify(reinterpret_cast<const uint8_t*>(value.data()), value.size() * sizeof(typename T::value_type), connHandle);
+            } else {
+                return notify(reinterpret_cast<const uint8_t*>(value.data()), value.size(), connHandle);
+            }
         } else if constexpr (Has_c_str_length<T>::value) {
             return notify(reinterpret_cast<const uint8_t*>(value.c_str()), value.length(), connHandle);
         } else {
@@ -212,7 +256,11 @@ class NimBLECharacteristic : public NimBLELocalValueAttribute {
     typename std::enable_if<!std::is_pointer<T>::value && !std::is_array<T>::value, bool>::type indicate(
         const T& value, uint16_t connHandle = BLE_HS_CONN_HANDLE_NONE) const {
         if constexpr (Has_data_size<T>::value) {
-            return indicate(reinterpret_cast<const uint8_t*>(value.data()), value.size(), connHandle);
+            if constexpr (Has_value_type<T>::value) {
+                return indicate(reinterpret_cast<const uint8_t*>(value.data()), value.size() * sizeof(typename T::value_type), connHandle);
+            } else {
+                return indicate(reinterpret_cast<const uint8_t*>(value.data()), value.size(), connHandle);
+            }
         } else if constexpr (Has_c_str_length<T>::value) {
             return indicate(reinterpret_cast<const uint8_t*>(value.c_str()), value.length(), connHandle);
         } else {
diff --git a/src/NimBLERemoteValueAttribute.h b/src/NimBLERemoteValueAttribute.h
index 7a92479a..bc76319b 100644
--- a/src/NimBLERemoteValueAttribute.h
+++ b/src/NimBLERemoteValueAttribute.h
@@ -109,13 +109,34 @@ class NimBLERemoteValueAttribute : public NimBLEValueAttribute, public NimBLEAtt
      * @brief Template to set the remote characteristic value to <type\>val.
      * @param [in] v The value to write.
      * @param [in] response True == request write response.
-     * @details Only used if the <type\> has a `data()` and `size()` method.
+     * @details Only used if the <type\> has a `data()` and `size()` method with `value_type`.
+     * Correctly calculates byte size for containers with multi-byte element types.
      */
     template <typename T>
 #  ifdef _DOXYGEN_
     bool
 #  else
-    typename std::enable_if<Has_data_size<T>::value, bool>::type
+    typename std::enable_if<Has_data_size<T>::value && Has_value_type<T>::value, bool>::type
+#  endif
+    writeValue(const T& v, bool response = false) const {
+        return writeValue(
+            reinterpret_cast<const uint8_t*>(v.data()),
+            v.size() * sizeof(typename T::value_type),
+            response
+        );
+    }
+
+    /**
+     * @brief Template to set the remote characteristic value to <type\>val.
+     * @param [in] v The value to write.
+     * @param [in] response True == request write response.
+     * @details Only used if the <type\> has a `data()` and `size()` method without `value_type`.
+     */
+    template <typename T>
+#  ifdef _DOXYGEN_
+    bool
+#  else
+    typename std::enable_if<Has_data_size<T>::value && !Has_value_type<T>::value, bool>::type
 #  endif
     writeValue(const T& v, bool response = false) const {
         return writeValue(reinterpret_cast<const uint8_t*>(v.data()), v.size(), response);
@@ -131,7 +152,11 @@ class NimBLERemoteValueAttribute : public NimBLEValueAttribute, public NimBLEAtt
     template <typename T>
     typename std::enable_if<!std::is_pointer<T>::value, bool>::type writeValue(const T& v, bool response = false) const {
         if constexpr (Has_data_size<T>::value) {
-            return writeValue(reinterpret_cast<const uint8_t*>(v.data()), v.size(), response);
+            if constexpr (Has_value_type<T>::value) {
+                return writeValue(reinterpret_cast<const uint8_t*>(v.data()), v.size() * sizeof(typename T::value_type), response);
+            } else {
+                return writeValue(reinterpret_cast<const uint8_t*>(v.data()), v.size(), response);
+            }
         } else if constexpr (Has_c_str_length<T>::value) {
             return writeValue(reinterpret_cast<const uint8_t*>(v.c_str()), v.length(), response);
         } else {