The Universal Phone Adapter is a stick-on adapter suitable for all types of smartphones and is also compatible with the bike stem mount included in the Bike Kit #7278. This adapter is also compatibile with other Zéfal holders. The Universal Phone Adapter can be used with all types of phones and cases except ones made from rubber, silicon, TPU and other soft materials. Choose a flat, non-pourous surface (e.g. hard plastics) to attach the Universal Phone Adapter to but once it has been fit, it cannot be removed or reused.