MCT-3 (DNT00089) MegaCode 3-button remote transmitter operating at 318 MHz. Each button sends a unique code—one for garage door activation, one for access gate control, and one for additional garage door operators or Linear 318 MHz MegaCode wireless receivers. No dip switches required; the receiver learns and memorizes each transmitter's digital code and activates only from programmed units. Features a high-visibility test/operate LED and spring-steel dual-position visor clip for vertical or horizontal mounting. Dimensions: 3.04 by 1.93 by 0.61 inches. Compatible with all Linear garage door openers. Powered by two Type CR2032 coin-cell batteries.