Using super heavy duty rubber, the TrailKASE is designed to conveniently fit any size phone with or without a case on your bicycle while you ride! Using an 1/8 turn (10 o'clock to 12 o'clock), the TrailKASE securely attaches to the handle bar bracket (included). By simply wrapping the rubber case around all 4 corners of your phone, your phone is secure and provides 100% visibility to your screen.