5 Fobs. These Evva branded proximity fobs are used to operate the Evva AirKey range of proximity locks, they are stylishly designed and robust, featuring a strong loop to allow the fob to be fixed to an appropriate keyring, key tag, streak or to be hung in a key cabinet.. Stylish Evva design. Used to operate Evva AirKey proximity locks. MIFARE DESFire EV1. Strong anchor point to attach to keyring, key tag or streak