I machined 25 balancers from aluminum bar stock. This balancer is made with 4 lb. rare earth magnets. I got an email from Andy Brown asking if my balancer would support the weight of a 3 1/4 inch diameter prop. To answer his question I put 3 ABC 2914-10 2 blade props on a shaft and it held. The price is $75.00 with your choice of the 1/8, 3/16 or 1/4 inch prop shaft. Extra shafts are $15.00 each. I have 1/8 and 1/4 inch shafts in stock but I need to order the 3/16 shafts. I accept cash, check, money order or PayPal. PayPal info is firstname.lastname@example.org Orders in by noon ship same day, after noon they ship next business day.