Topeak Smartphone Dry Bag for 4-5-Inch Screen Phones Used by both professional and amateur riders alike Made using high quality materials and components Tested to ensure quality and durability Great for using smartphone for GPS, mapping, cycling apps ,and music Waterprood material is sonically welded and seam sealed to repel weather for ultimate phone protection Quick Click sytem can be mounted on handlebar or stem. It provides fast on/off and swaps between bikes Optional Ridecase mount,