Product Info Catalog Hardware Fasteners Hitch Pins PTO Wirelock Pin, Square, Yellow Zinc-Plated, 5/16 x 2-1/4-In., 2-Pk. PTO Wirelock Pin, Square, Yellow Zinc-Plated, 5/16 x 2-1/4-In., 2-Pk. Request a Quote UPC: 32874319803 SKU: 179905 Model Number: 31980 5/16" x 2 1/4" square pto lock pin 2pk, wirelock pin, shaft diameters from 1/4" to 3/8" ,round or square wirelock, yellow zinc plated. 5/16" X 2 1/4" Square PTO Lock Pin 2pk Wirelock Pin Shaft diameters from 1/4" to 3/8" Round or square wirelock Yellow zinc plated