Description 1" SAE LH Thread, 1-3/8" Diameter Shoulder Bolt for Rotary Cutter Blade. Fits Servis, Cyclone 60, 72, 84, 128, Flex 15, Gyro 60, 72, 84, 128, 160, 1310. Made in the USA. This item is a suitable alternative for the following: 404-165230, 404165230, 2924, 2301404-165230, 2299, 57-104-4, BB54, 571044, 57104-4