Review on Genie GM3T-R Intellicode 9/12 Dipswitch Garage Door Opener Remote (2 Pack) - Compatible With Openers Since 1993 by Pete Juarez

There are a couple of You Tube videos explaining how to set up the "dip" switches. so if you are unsure, just watch. The one You Tube had the Intellecode at the beginning, but wait until closer to the end to learn about the dip switches. just copy your old remote, or open the front light panel on the unit in the garage and take a photo of the switches on the left side. DON'T TOUCH the right side. copy. Hold down "C" until the light comes on (12 dip switch setup for me) and press the middle on-off switch on the front until it blinks green. make sure the front is green. if red, you have to go back and press the "C" light again.