Zefal Universal Phone AdaptorUniversal Smartphone Holder The Universal Phone Adapter is a stick on adapter suitable for all types of smartphones. This adapter is compatibile with Zfal 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