Material: SUS304 Stainless steel lead screw + copper nut Lead Screw Length: 400mm;Lead Screw Diameter:8mm Screw pitch: 2mm; Lead: 8mm Thread: Acme thread,Copper nut:with 4 holes for fixing to the machine . WHAT YOU GET: 2pcs 400mm Tr8x8 Lead Screw With T8 Brass Nut. 30-Days money back guarantee, 1-Year warranty, 24/7 friendly customer service.