Please note this is a third-party transmitter, not original. Compatibility List: RSC 2 RSE 2 Compatible Motor/Drive: Liftronic 500, 700, 800 (Not compatible with Liftronic 700-2 & 800-2 from February 2021) Portronic D5000, S4000, D2500 Pairing Instructions: Press the 'P' button on the drive unit; the red LED will flash slowly. Press the corresponding button on the compatible remote; the LED on the drive unit will flash faster. Press and hold the same button again within 15 seconds; the LED will flash rapidly. The red LED will then illuminate constantly, indicating successful programming. Specification: Frequency: 433.92MHz (433MHz) Buttons: 2, DOWN button Chip: HCS301 Battery: 12V/27A Alkaline Operating Range: 30-50 meters outdoors Keychain and battery included Advantages: 1. Imported HCS301 chip and SAW crystal ensure stable and lasting operation. 2. Simple, modern, and compact design. 3. Experienced manufacturer with 3 times QA testing for quality assurance.