Linear 3089 Multi-Elmac 1-Button 300 Mhz Visor Garage Door Opener Remote Control

This looks like my remote, but how do I know if it's the right one?

alternate names 3089-11, multi-elmac, 1089 (1970's) version ALL the same remote.

1. Frequency: Check the back of your remote to make sure the frequency of the remote is 300mhz (megahertz).
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 10 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
Multi-ELMAC gate or garage door opener model 3089 hand held remote control 300 MHZ Frequency gate or garage door remote transmitter 10 (binary) dip switches Visor clip, 9V battery and one year warranty included Compatible with ALL US Multicode gate or garage door opener systems