The Snap-on Tools 4-pc Wheel Hanger Set, No. WHS4, is made up of four tools that hold the wheel in place when removing and installing bolts while trying to balance the wheel. All four pieces feature a 10mm hex and range in thread size that can be installed by hand, wrench or air ratchet, the company says. This set is designed to make the task faster and safer for technicians, and is ideal for technicians doing a lot of wheel service work.