7 16 x.550, Gold Heavy duty to allow repeated use with a fastener tool allen wrench or a ratchet without stripping A larger size distributes the load over a larger area to avoid pull-though The spring holds the button captive so that it can't be dropped underneath the car or into some hard-to-get-at area of the chassis A necessity for quick pit work in racing Use with Spring Nos. 71400, 71410, 71420, 71425 or 71430 Ten per package