The Rapfix II uses a patented ball locking design which will not come off during driving but allows for quick and easy removal. No play whatsoever, this is the ORIGINAL! The piece is a cold forged aluminum body, which is track tested and proven by the top Japanese race drivers. Makes it easier to get in and out of your car, and also provides added security when parked. This quick release will only bolt to 6 bolt Momo, Sparco patterned hubs or 12 bolt multipattern hubs.