This looks like my remote, but how do I know if it's the right one?
1. Frequency: Check the back of your remote to make sure the frequency of the remote is 390mhz (megahertz) or says Liftmaster, Chamberlain, or Sears Craftsman. All of these use the same frequency of 390mhz.
2. Dip Switches: Open the battery compartment on your old garage door remote and look to see how many dip switches (tiny switches in a row) it has. If your old remote had 9 dip switches, then it's a match for this remote. If you don't have your old garage door remote, you can also look to see how many dip switches are on the back of your garage door opener (the overhead unit in your garage). The number of dip switches on the back of the opener is the same as on the remote. Features and Specifications 390 MHZ Frequency, works on models from 1984-1992 1 set of 9 three position dip switches 12V battery and visor clip included

Also compatible with wireless keypad model number 66LM (same as model 740CB, 139.53776, 139.53876) Sears Craftsman Compatible Model #'s 139.53100 139.53608 139.53110 139.53609 139.53200 139.53610 139.53210 139.53611 139.53300 139.53612 139.53310 139.53613 139.53315 139.53614SR 139.53315SR 139.53615SR 139.53400 139.53618SR 139.53403 139.53619SR 139.53413 139.53622 139.53415SR 139.53625SR 139.53500 139.53632 139.53513 139.53632SR 139.53600 139.53639 139.53601 139.53639SR 139.53602 139.53651 139.53603 139.53651SR 139.53604 139.53699SR 139.53605 139.53708 139.53606 139.53718 139.53607