made from  aluminum fairly sturdy on my huge invicta band i had to make a band holder out of piece of 2x4 about 2.5 " cut a slot 3/8 wide/3/4 deep  (cut on table saw ) with holes drilled for pin to come out & used pin part  of this tool as a punch & it worked i thought i would have to buy a bigger tool for band but this worked i had that red aluminum one they sell here which is good but i can't find it so somtimes you have to improvise & on this tool if band is to big if you have a vise & a hack saw you can make tool bigger by cutting it with saw i know most people don't have a garage full of tools but in this world you have to be creative