The Arm – Helmet Extension For GoPro Key Features Attaches to helmet mount for 180 degree POV shots Extends any GoPro or GoPole Mount Lightweight Attaches Directly to all GoPro HERO Cameras The Arm with Mount for Helmet, 360 degrees rotation, with lock, with 3M sticker For Gopro Attachable to helmet mount, convenient for video recording Perfect angle design, light-weight but sturdy and durable Come as arm QD Buckle, helmet use curved surface and 3M VHB Adhesive Sticky Compatibile with GoPro HERO4, GoPro HERO3+, GoPro HERO3, GoPro HERO2, GoPro HERO1, SJ4000, SJ5000, SJ6000, Xiaoyi Max Length : 19.5cm; Size : 19.5*1.3cm