Rec-mounts&trade; Bike Bar Mount (22.2mm/25.4mm/26.0mm) (Rec-b21-gp(bk) for Gopro&reg; Camera for GoProHD HERO HERO2 HERO3 HERO3+ HERO4 only Clamp size 22.2mm/25.4mm/26.0mm Only GoPro adapter is removable Adapter number REC-B34 1/4 camera screw holes. 6061 T6 Aluminum Weight 82g Color Silver or black facebook https://www.facebook.com/recmounts cycle catarog(PDF) http://www.an-y.com/img/rec-mount-catalog3.pdf