Zinc plated steel threaded inserts.M4 Regular Threaded Insert (Rivet Nut) - Pack of 50• Regular zinc plated threaded inserts.• Model No. TIRM4Model No: TIRM4:Brand: Sealey:Grip Range: 0.5-2mm:Nett Weight: 0.00kg:Pack Qty: 50:Thread Size: M4 x 0.7mm:Type: Regular:PTDSEATIRM4