The 37559R.S sprocket is for chain drive garage door openers. The sprocket kit attaches to the motor head on your chain drive garage door opener. It drives the chain to move the garage door. Always unplug your automatic garage door opener before replacing parts.
Use With Opener Models: 1028, 2028, 3020H, 3020HB, 3024, 4024, 3022, 4022
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