The Bow-Tie Locking Cotter Pin works like a Hair Pin Cotter but locks securetly into place. 

The Bow-Tie snaps into a zero-tension locked position - resisting vibration and accidental disengagement. It can easily be removed by lifting the loop and sliding the cotter off. 

Numerous sizes available to fit shafts 3/16" through 1". Available in Zinc-Plated steel, 400 series stainless steel, or 17-7 stainless steel.