Compatibility: Perfectly matches with for Guardian 2211L systems, ensuring seamless operation Advanced Technology: Utilizes a 303MHz frequency with rolling code technology to enhance security by generating a code with each use, preventing unauthorized access Design: Crafted for durability and reliability, ensuring long-lasting performance in various weather conditions Easy Programming: Simple setup process allows for quick and hassle-free programming, your remote control operational in no time Specifications Encoding method:Rolling code Frequency:303MHz Button:2 Use:Electric Door Code:Rolling code (The product printed words depending on the batch, but this does not affect use) Color: As Shown Material: ABS Package Contents: 4 x 303MHz Rolling Code Transmitter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.