Professional Quality, manufactured from chrome vanadium electric steel, oil hardened, tempered and chrome plated, with smoothly ground jaws, joint faces and an accurately formed box joint with safety stop. The parallelogram-shaped gripping surfaces have specially hardened teeth to 61HRC for positive grip on pipes and nuts. One hand press button adjustment.Heavy duty moulded handles with slip guards for extra safety. Has 'no-nip' feature which prevents handles locking together and damaging users' hands.