diff --git a/docs/en/unit/accel.md b/docs/en/unit/accel.md
index 17ed04b7..9ea9d59c 100644
--- a/docs/en/unit/accel.md
+++ b/docs/en/unit/accel.md
@@ -20,9 +20,17 @@ By measuring the amount of static acceleration due to gravity, you can find out
 <img src="assets/img/product_pics/unit/accel/accel_03.jpg" width="30%" height="30%">
 
 ### Product Features
-- Tiny
-- ultralow power
-- 3-axis accelerometer
+
+- Supply voltage range: 2.0 V to 3.6 V 
+- Ultralow power: as low as 23 µA in measurement mode and 0.1 µA in standby mode at VS = 2.5 V (typical)
+- Single tap/double tap detection 
+- Activity/inactivity monitoring 
+- Free-fall detection
+- I/O voltage range: 1.7 V to VS 
+- I2C digital interfaces 
+- Wide temperature range (−40°C to +85°C)
+
+
 
 ## Include
 
diff --git a/docs/sidebar.md b/docs/sidebar.md
index 1f43217e..93d1ca5c 100644
--- a/docs/sidebar.md
+++ b/docs/sidebar.md
@@ -15,7 +15,7 @@
 
 
 <div class="container">
-    <a class="nav-link" href="#" data-toggle="collapse" data-target="#Product">> Product Documents</a>
+    <a class="nav-link" href="#" data-toggle="collapse" data-target="#Product"> » Product Documents</a>
 <div id="Product" class="collapse">
 <div class="container" style="margin:10px">
   <div class="btn-group-vertical">
@@ -270,10 +270,10 @@
 </div>
 
 
-<a class="nav-link" href="#/en/api">> Arduino API</a>
-<a class="nav-link" href="#/en/case">> M5Stack Cases</a>
-<a class="nav-link" href="#/en/related_documents">> Related Documents</a>
-<a class="nav-link" href="#/en/faq">> FAQ</a>
+<a class="nav-link" href="#/en/api"> » Arduino API</a>
+<a class="nav-link" href="#/en/case"> » M5Stack Cases</a>
+<a class="nav-link" href="#/en/related_documents"> » Related Documents</a>
+<a class="nav-link" href="#/en/faq"> » FAQ</a>
 </div>
 
 
diff --git a/docs/zh_CN/sidebar.md b/docs/zh_CN/sidebar.md
index 939494c0..266f3b2e 100644
--- a/docs/zh_CN/sidebar.md
+++ b/docs/zh_CN/sidebar.md
@@ -5,7 +5,7 @@
 - [常见问题解答](zh_CN/faq) -->
 
 <div class="container">
-    <a class="nav-link" href="#" data-toggle="collapse" data-target="#Product">> 产品文档</a>
+    <a class="nav-link" href="#" data-toggle="collapse" data-target="#Product"> » 产品文档</a>
 <div id="Product" class="collapse">
 <div class="container" style="margin:10px">
   <div class="btn-group-vertical">
@@ -260,10 +260,10 @@
 </div>
 
 
-<a class="nav-link" href="#/zh_CN/api">> Arduino API</a>
-<a class="nav-link" href="#/zh_CN/case">> M5Stack 案例</a>
-<a class="nav-link" href="#/zh_CN/related_documents">> 相关文档</a>
-<a class="nav-link" href="#/zh_CN/faq">> 常见问题解答</a>
+<a class="nav-link" href="#/zh_CN/api"> » Arduino API</a>
+<a class="nav-link" href="#/zh_CN/case"> » M5Stack 案例</a>
+<a class="nav-link" href="#/zh_CN/related_documents"> » 相关文档</a>
+<a class="nav-link" href="#/zh_CN/faq"> » 常见问题解答</a>
 </div>
 
 
diff --git a/docs/zh_CN/unit/accel.md b/docs/zh_CN/unit/accel.md
index bcfec5b3..2632ece5 100644
--- a/docs/zh_CN/unit/accel.md
+++ b/docs/zh_CN/unit/accel.md
@@ -20,9 +20,15 @@
 
 ## 产品特性
 
-- 体积小
-- 低功耗
-- 3轴加速度计
+- 电源电压范围：2.0 V至3.6 V 
+- 低功耗：VS = 2.5 V时(典型值)，测量模式下低至23 µA，待 机模式下为0.1 µA 
+- 单振/双振检测 
+- 活动/非活动监控 
+- 自由落体检测 
+- I/O电压范围：1.7 V至VS
+- I2C数字接口
+- 宽温度范围(−40°C至+85℃)
+
 
 ## 套件清单
 
@@ -63,8 +69,7 @@
 
 ## 相关链接
 
-- **[-数据手册](https://github.com/m5stack/M5-Schematic/blob/master/datasheet/ADXL345_cn.pdf)**
-
+- Datasheet - **[ADXL345](https://github.com/m5stack/M5-Schematic/blob/master/datasheet/ADXL345_cn.pdf)** 
 
 ### 管脚映射
 
@@ -79,3 +84,5 @@
 <video width="500" height="315" controls>
     <source src="https://m5stack.oss-cn-shenzhen.aliyuncs.com/video/Product_example_video/ACCEL.mp4" type="video/mp4">
 </video>
+
+