ERGONOMIC ALUMINUM BODY- The body of the knife is made of a durable aluminum alloy and steel so it can stand up to daily use better than plastic bodied box cutters. The body also features an ergonomic arc design that is more comfortable to use. RETRACTABLE AND SAFE- The retractable knives feature a lock back design that safely locks the blade into place and makes changing blades easy. It unfolds quickly when needed and folds back with a push of a button to keep you safe when not in use. HEAVY DUTY- Each razor features heavy duty construction with a simple design. The set contains 3 knives and 9 replacement blades but accepts all standard utility blades. The body also features a stainless steel belt clip to keep the knife close. MULTIPURPOSE- This set of utility knives are perfect for a wide range of uses from contractor use, to craft or DIY home projects and more. Use it for breaking down or opening cardboard boxes, cutting carpet or linoleum, shaping wood or trimming rubber. PRODUCT DETAILS- Materials: Aluminum Alloy and Steel. Open Knife Dimensions: 6” L x .7” W x 1.2” H. Folded Knife Dimensions: 3.5” L x .7” W x 1.2” H. Set of 3. Includes 9 Replacement Blades.