The ADI combination wrench, #10015, is made from machined steel, hardened, and has a black finish with the ADI logo and sizes laser engraved. You wont have to worry about the wrench ends spreading open or changing size after just one use compared to other aluminum wrenches. The 7mm end can be used with the standard M4 nut, Losi 5ive turn buckles, and some of the nitro engine high speed needle housing. The 8mm end works with M5 nuts and the OS style nitro engine high speed needle housing. This wrench is a perfect fit in your tool box if you have a 1/5th scale in your RC fleet.