These Knipex 250mm Cobra Water Pump Pliers are manufactured from chrome vanadium electric steel, oil hardened & tempered, with smoothly ground jaws, joint faces & an accurately formed box joint with safety stop. The parallelogram-shaped gripping surfaces have specially hardened teeth to 61HRC for positive grip on pipes & nuts. Featured is one hand press button adjustment for ease of use. The handles are plastic coated with slip guards for extra safety. These pliers also have a 'no-nip' feature which prevents handles locking together & damaging the users' hands.