The 41A5021 chain drive gear kit uses a chain to drive the opener system as shown above. The parts numbers below use a chain like the one above.
Note: You must have a chain like the one above for this gear kit to work.
Chain Drive Units: 41A5021-1, 41A5021-1a, 41A5021-1b, 41A5021-1c, 41A5021-1d, 41A5021-1e, 41A5021-1f, 41A5021-1g, 41A5021-1h, 41A5021-1i, 41A5021-6e, 41A5021-6f
Chain Drive Units: 41A5021, 41A5021-b, 41A5021-c, 41A5021-d, 41A5021-e, 41A5021-f, 41A5021-g, 41A5021-h, 41A5021-i