Trying to find replacement gears for your operator online takes a good bit of digging. Luckily you have North Shore Commercial Door to go to work for you. With over 35 years of experience in the market, we know product quality, and a great deal when we spot one.
The Guardian GUAT-311 is part of the limit system Drive Gear. This is a bevel (90 Degree) gear that transfers the rotation of the operator output shaft to the driven gear on the limit switch lead shaft on which limit contact travels (which sets the travel limits).
This particular gear was used on Guardian Models 315, 415, and 425.