Hydraulic Knockout Kits - The RIDGID unique 3-point design makes punching fast and simple. Combines ease of hydraulic operation and precision-ground knockouts to provide clean, quick holes. Available with foot or hand pumps. Precision-ground 3-point punch/die sets. Capacity to 4" in 12 gauge mild or 14 gauge stainless steel. Powerful 11-ton hydraulic ram. Pumps equipped with internal safety relief valve. Ram and pump equipped with quick disconnect couplers.