PTO Shaft Locking Pin 7/16" x 3-1/2" (Pack of 3): Amazon.com: Industrial & Scientific
Wirelock Pin, Round - 1/2" x 3" x 3 1/8" | Agristore USA | AGRISTORE USA
VEVOR PTO Drive Shaft 1-3/8 in. PTO Driveline Shaft 6 Spline End Round End 39 in. to 55 in. for Bush Hog Series 4 Tractor CDZT4B10004055001V0 - The Home Depot
PTO Shaft Locking Pin 1/4" x 2-1/4" ( PACK of 10): Amazon.com: Industrial & Scientific
PTO Push Pin for Tractor Yoke Locking Device fits most North American Yokes | eBay