433.92MHz Grey Back Only: Ensure your remote operates at 433.92MHz and has a grey back. Not compatible with Digital 868MHz remotes with black back. Not compatible with Bi-Linked series. Compatibility List: This is a replacement for 433.92MHz Multi-Bit remote controls. Compatible with Digital 302, 304, 306, 313, 317, 318, 321, 323, 382, 384, 392, 394 433MHz models. Compatible with 131, 132, 222, 231 433MHz models. List of compatible garage door opener receivers: This remote control works only with garage door opener receivers operating at 433.92MHz Multi-bit frequency. Compatible with Comfort 50, 51, 60, 211, 220, 220.2, 250, 250.2, 252, 252.2, 500, 510, 520, 580, 800, 820, 830, 850, 851, 870. Warm Tips: This garage door remote control is a replacement unit and not an accessory. Check device compatibility using the list above before purchase. Material: Plastic Color: As shown Package Contents: 2 x Remote controller Only the items listed above are included; other products are not included. Note: Lighting reflections and display differences may cause slight variations between the color of the item in the image and the actual product. Measurement may vary by +/- 1-3 cm.