The Cruz Quantum Slider Case lets you secure and use your phone inside a maximum radiation protective case cover. Match your phone size to either the mid-size 4.5″-5.2″ (11.43cm x 13.2cm) case or to the large 5.5″-6″ (13.97cm x 15.24cm) Cruz Quantum Case. Then press your phone with or without its current case onto the SureGrip slider pad. Be sure to clean the back of the phone first. Slide phone up to take picture. Slide back into case for complete protection.