Specification : Material of body: Steel Rivet nut material: Aluminum alloy Material of handle cover: Rubber Color: Blue + black+silver Total length of hand tool: approx.17cm/6.6" Size of nut rivet mandrels: M3/M4/M5/M6/M8 M3: for sheet with thickness from 0.5mm to 2mm M4: for sheet with thickness from 0.5mm to 2mm M5: for sheet with thickness from 0.5mm to 2.5mm M6: for sheet with thickness from 0.5mm to 3mm M8: for sheet with thickness from 0.5mm to 3.5mm Features: Rivet nuts are made from aluminum alloy which provides strength, corrosion protection and long service life. Includes wrench to hold handles and adjust mandrels. Ergonomic tool, made of steel with non-ip handle. Durable, easy to use. Suitable to be used in car, trailers, and furniture repair, or even boat building. With open end, small flange, round hole, threaded inner wall and partial anti-skid surface, these flat head rivet nut has a good performance of fastener function. There are various sizes, M3, M4, M5, M6, M8 and they normally have low profile compared to other nuts. Each size includes many pieces of rivet nuts so you don't have to go to hardware store searching rivet nuts for a while Comes with a riveter and many mandrels and nosepieces for convenient riveting includes: 1 x Nut Rivet Tool 5 x Nut Rivet Mandrels: M3/M4/M5/M6/M8 20 x M3 Threaded Rivet Nut Inserts 20 x M4 Threaded Rivet Nut Inserts 20 x M5 Threaded Rivet Nut Inserts 10 x M6 Threaded Rivet Nut Inserts 10 x M8 Threaded Rivet Nut Inserts 1 x Plastic Storage Case 1 x Instruction Manual