Buck Algonquin Prop Knockers - Propeller Removal Tool The Buck Algonquin Prop Knocker is a special tool designed to “Pop your Prop”. Just remove your propeller nuts and thread this part on the end of your shaft. Give the casting a few taps and your propeller will work its way loose. The Buck Algonquin Prop Knocker is made of Nibral and threaded to fit shafts with the SAE J755 specification. Several shaft sizes are available for Buck Algonquin Prop Knockers.