Quad Lock Out Front Bike Mount Heads up position provies better viewing angle Patented dual-stage locking mechanism ensures your phone is held securely to your bike Can be rotated for over stem mounting Suits handlebar sizes 31.8mm and 25.4mm Compatible with all Quad Lock Cases. Optional GoPro Adaptor also available (not included) 1x Quad Lock Out Front Mount - suits 1-1/4&#034; (31.8mm) bars 2x Bar Spacers - 7/8&#034; (22mm), 1&#034; (25.4mm) 1x Allen (Hex) Key Glass filled nylon / polycarb construction with stainless steel hardware Suits bar sizes 1-1/4&#034; (31.8mm), 1&#034; (25.4mm) &amp; 7/8&#034; (22mm) Patented dual-stage, spring-loaded locking mechanism Compatible with all Quad Lock Cases and Universal Adapters (not included)