This copper/brass rivet fixing tool is made to fit the 10 gauge size of rivets and washers.
The hole in the end is used to tap your washer down over the stem of the rivet, and once you've cut off any excess length with pincers / end cutters (leaving 3-4mm of stem beyond the washer) you then place the round dented part of the tool on the end of your rivet stem and hit the tool with a mallet to mould the stem down over the washer.
