Down & Dirty; It’s what we called them during their development. Shooters that put a LOT of rounds down-range (3-gunners, etc.) like to check the headspace in their weapons periodically, but are reluctant to pay for a number of sets of our standard Gauges. We wanted to take as much cost out of the most popular headspace Gauges as we could without sacrificing precision or utility in order for shooters to afford the Gauges they needed.