Check the listing for details. Linear ACT Visor Transmitter, Block Coded, 1-Channel (DNT00052A/MDT-1A). Color: N/A, Condition: New. Listed at 28.66 USD. The Linear MDT-1A 1-Channel Visor Transmitter is designed for use with Linear’s access control products. The MDT-1A is a single-channel device. Pressing either the round button on the transmitter’s front, or the small button on the transmitter’s top will send the same signal. The top button can be hidden with the top button cover supplied. Also included are lithium batteries with a five-year service life and a visor clip. The transmitter is MegaCode format, which means each transmitter is factory preprogrammed with one of over 1,000,000 codes, virtually eliminating the possibility of code duplication. Because the receiver "learns" each specific code, no unauthorized person can gain access to the system by reprogramming a transmitter.Compatible with all Linear access receivers and controllersSuperior transmission rangeFactory programmed MegaCode format supports over 1,000,000 codesUnique "Extra" top buttonHigh visibility operate LEDVisor clip included Models compatible with the MDT-1AAE1000Plus: Commercial Telephone Entry System with Access Control - Four DoorsAE2000Plus: Commercial Telephone Entry System with Access Control - Four Doors, Large ScreenAKR-1: Exterior Digital Keypad with Radio ReceiverAM-RPR: Remote Proximity ReceiverAM-RRR: Remote Radio ReceiverMDR: 1-Channel ReceiverMDR-2: 2-Channel ReceiverMDRG: 1-Channel Gate ReceiverSMDRG: 1-Channel Gate ReceiverWOR: Wiegand Output Receiver Technical DetailsBattery Life: Up to five yearsFrequency: 318 MHzNumber of Codes: 1,000,000+ (MegaCode format)Channels: one channelPower: Two 3V 2032 type lithium batteries (supplied)Dimensions: 1.6" W x 4.2" H x 0.8" D (41 x 107 x 20 mm)Manufacturer Part No: DNT00052A