QuestCraft 7pc Split Ring Drill Bit Stop Collars Set Exact Hole Depth Brad Point Bits Feature the "split-ring" design which positively locks anywhere along the bit diameter. Unlike setscrew type collars that may skew/amage the bit, these units won't move after tightening. Work on both standard and brad-point bits.The set includes a hex key and 1/8", 3/16"