This J-Hook Buckle can be used with flat surfaces,especially helmet and chest belt Camera by holding your Series and making your usage convenient. Made of metal Easy operation, easy to install and remove Link with waterproof shell, bicycle, etc Used for SJ400 Car DVR and outdoor sports camera, Accessories kits compatible for 5/3/3+/4/Hero5 Black/ 4 Black and Sliver/ 2 , Style cameras ,like m1/ 4k/ 4K plus/ SJ4000/SJ4000 WIFI/SJ4000 Plus/SJ5000 series/SJ6000/SJ7000/SJ8000/SJ9000 SJ7/0SJ6/SJ7 star/SJ8000/SJ9000/m10/m20 mount, Accessories for H9/h9r and other name action cameras 6.Functions Can connect with related accessories, such as waterproof case.Can install to the bicycle 7.This accessories can used to fix helmet/surfboard/chest strap and other sports ,give you more angle color: black Package Contents: 1 x J-shaped buckle, 1 x Long screws + nuts 1 x Flat Base 1 x Activities base 1 x 3 to adjust the arm 1 x Fixed rope ( Not include other product) Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.