BLOX Racing intake and exhaust studs are CNC-machined from SUS303 stainless steel. Each stud features precision threads and includes a washer and 12-point hex nut. Material: SUS303 stainless steel. BLOX Racing SUS303 Stainless Steel Intake Manifold Stud Kit M8 x 1.25mm 55mm in Length - 10-piece.