This transmitter is a four-channel device. Each button activates one of the four channels. The buttons feature raised dimples for easy, or vision-impaired identification. The transmitter is Multi-Code format with two 10 position-coding switches providing 512 possible codes for each channel. The transmitter will only activate receivers set with the same code. The Model 414001 is compatible with 300 MHz Multi-Code receivers and Model 109950 and 302850 receivers. Compatible with 300 MHz Multi-Code receivers Supplied with visor clip. Easy access to battery and coding switches. Power: 9-volt battery. Codes: 512 codes for each channel (set by dip switches). RF frequency: 300 MHz. Dimensions: 2.5" W x 3.75" H x 0.875" D. The Model 414001 4-Channel Visor Transmitter is a portable transmitter designed for automatic door and gate operator applications. A visor clip is included. The transmitter is powered by a 9-volt battery and has a test/operate indicator.