This is a set of imperial setup and marking blocks used for quick, repeatable marking and measuring without messing with a ruler or tape to line up marks.

Each block has a small lip to easily and quickly measure and mark from the edge of an object. This set includes sizes, .375",.5",.75",1",1.25",1.375", and 1.5" each block is .75" wide and .5" tall for accurate reference. This is not a super complexed model but I have found it to be one of my most common tools I reach for in my shop for quick and accurate marking.