Garage Door Transmitter

Here’s the description from Amazon, which is also selling it for only $13.77 (less than this price plus shipping).

1 button transmitter for garage door openers with Linear radio controls.310 Mhz frequency visor size remote control transmitter.8 Switches Code Set for easy programming.Compatible with ALL Linear/ Moore-o-Matic Delta 3 System products.Compatible with the Homelink System.Visor clip and 9V battery included, 1 year manufacturer warranty.