HSU All Aluminum Alloy Extension Arm Kit & NVG Helmet Mount for GoPro/DJI/Insta360Product Description All Aluminum Alloy Extension Arm Kit: 3 x aluminum alloy extension arms of different lengths (11. 8 6. 5 3. 3) + 3 x aluminum alloy screws + 1 x aluminum alloy wrench (fix the screws at the connection) 1 4" & 3 8" Hole: Standard 1 4" and 3 8" screw holes, can be installed as expansion accessories according to your needs Multi Purpose: The extension arm mount kit can be assembled into an extension pole, selfie stick, stabilizer,