Mini 4 Button Transmitter This convenient size transmitter allows you to control up to four separate doors. Features Instructional Videos Hörmann SilentDrive® Garage Door Opener - Resetting and Retraining HSM4 Mini-Transmitter Programing FCT3B Wireless Keypad Programing FCT3B Wireless Keypad PIN Number Change FCT3B Wireless Keypad Factory Reset