Description Fits 300/500/600 series two-stage snow thrower models, 2005 and after. For Troy-Bilt, MTD, Yard-Man, Yard Machines, Huskee and Bolens units. Easy to install. Replaces O.E. No. 738-04124, 738-04124A. Includes four shear pins and four clips. 1/4" x 1-/2" pin size. Helps protect a snow thrower from damage when the impeller comes in contact with a solid object. MTD Genuine factory parts sheer pins. WARNING: This product can expose you to chemicals including Lead which is known to the State of California to cause cancer, birth defects or reproductive harm and Butyl Benzyl phthalate (BBP) which is known to the State of California to cause birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov