diff --git a/en/btlib/bt.md b/en/btlib/bt.md
index 47692e132832e9c5b01ea0257feae98412bfc481..483536599349c388bda6f64103136e120daa2f26 100644
--- a/en/btlib/bt.md
+++ b/en/btlib/bt.md
@@ -1553,3 +1553,4 @@ Sends data through SPP.
 
 - `0`- Successful execution; `-1`- Failed execution.
 
+> **Note**: The maximum single transmission size is 4008 bytes. It is recommended to send in 667-byte segments. A return value of -1 usually indicates that the buffer is full. In such cases, a longer delay should be used for transmission.
\ No newline at end of file
diff --git a/zh/btlib/bt.md b/zh/btlib/bt.md
index 60a5155a6b57f9160f82021bc0aec50c0cd8736c..567a45616ee46f7ee02ee57bd986b989e05359bf 100644
--- a/zh/btlib/bt.md
+++ b/zh/btlib/bt.md
@@ -757,3 +757,4 @@ bt.sppSend(data)
 
 执行成功返回整型0，失败返回整型-1。
 
+> 注意：单次发送最大4008字节，建议按照667字节分片发送；返回-1一般是buffer满导致，需要加大延时发送。