433.92MHz Grey Back Only: Ensure your original remote operates at 433.92MHz and has a grey back. Not compatible with Marantec Digital 868MHz remotes with black back. Not compatible with Marantec Bi-Linked series. This remote is a replacement for Marantec 433.92MHz Multi-Bit remote controls. Compatible with Marantec Digital 302, 304, 306, 313, 317, 318, 321, 323, 382, 384, 392, 394 433MHz models. Compatible with Marantec Command 131, 132, 222, 231 433MHz models. Works only with garage door opener receivers operating at 433.92MHz Multi-bit frequency. Compatible with Marantec Comfort 50, 51, 60, 211, 220, 220.2, 250, 250.2, 252, 252.2, 500, 510, 520, 580, 800, 820, 830, 850, 851, 870. This garage door remote control is a replacement and not an original 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 are included; other products are not included. Note: Lighting and display differences may cause slight color variations between the image and the actual item. Measurement may vary by +/- 1-3 cm.