First, start with what brand your garage door opener is by checking the owner's manual or calling a garage door professional. If you have a Liftmaster, the easiest way is to check the color of the smart or learn button. The manuals explain that if you have a green, orange, yellow, or purple learn button, this is the replacement remote control you need. If you call us, we can also give this information to you. One suggestion is to buy a universal remote compatible with any of a manufacturer's products.