Sunsbell&reg;Generic Waterproof Bicycle Handlebar Bag Mount Holder with Full Body Case for Sumsung galaxy S3 S4 S5 Heavy duty suction cup and lock clip to make sure your devices stays in place Soft foam inside two mounting arms to hold the product anti-slide, shock-proof, and anti-scratch Waterproof proctective case with Transparent Touch Through Cover 360 degree rotation swivel holder allows you to hold your device to any angle The diameter of this Bicycle Mount Holder is 20mm. Choose the best section to fix.