The Scorpion HK-22mm series of motors are built with 3mm hardened steel shafts that will last through countless hours of flying fun, but occasionally, on a "Less than Perfect" landing, you may bend or break one. For these occasions, we offer factory repalcement shafts for all the HK-22mm Scorpion Motors. Our Motor Shaft Kits include an original equipment factory shaft with the setscrew keyways already cut, a new spacer washer, and a set of 3 retaining clips. This way, when one goes flying and bounces off the wall while you are trying to install it, never to be found again, you still have a couple more to try again! The shaft for the HK-2213 series motors measures 3mm in diameter, and is 47.5mm in long. The shaft kit will also fit other brushless motors that require a 3mm shaft of this length. The shafts can be cut shorter with a Dremel tool and a cut-off wheel if necessary to fit other motors. Note: The shafts in the Scorpion motors are a slight press fit into the aluminum front housing. The shafts will not just slide out when the setscrews are removed. They need to be pressed out in a bearing press, or in a drill press, with the front houshing of the motor supported in a block of wood to prevent warping the front housing. Also, these shafts are 3mm from end to end. The stock shafts are 3.175mm (1/8") on the output end, and 3mm where they go through the bearings. These shafts are offered for people that already have a large number of 3mm pinion gears, and want to swap the motor over to take 3mm pinions.