Commodity parameters
Large: height 4.2cm, width 3.3cm, weight 2.8g
Small size: height 3.8cm, width 3.1cm, weight about 2.5G

Note:
How to choose the right size and measure the width of the knuckle you need to wear,

1.3cm-1.5cm suggest small size, 1.5cm-1.8cm suggest large size