1'' Diameter 360 Degree Ball Head with Custom Hero Camera Adapter for GoPro Hero 1, Hero 2, Hero 3, Hero 3+, Hero 3 Plus, Hero 4 Camera RAM Mounts Compatible with GoPro Hero1, Hero2, Hero3, Hero3+ and Hero4 cameras Diameter (cm): 2.5 (1'') Mounts to many RAM double socket arms and mounts Multiple articulation and adjustment points for perfect viewing angles Package included: Ball Head Adapter x 1 (GoPro camera, housing and thumb screw are NOT included); Free touch screen stylus pen is included (Random color shipped)