The Tekton 87-pc 1/2" Drive 6-Point Impact Socket Set, No. SID92407, features a 6-point socket opening to provide an exact fit for hex fasteners, preventing fastener round-off. The size is marked in two ways on every socket, both as a high-visibility laser marking and a permanent stamped marking. The narrowed socket diameter goes all the way down to the base of the socket on small, deep-length sizes. This allows for better reach into tight, recessed areas. Whether in standard or deep length, the interior well extends far into the socket, which allows better fastener engagement in more situations.