X-ACTO Designer Series Knife has a premium, soft grip and an ergonomic handle to provide extra comfort. The rear blade release allows you to change the blades safely and easily. The knife includes the No. 11 blade for the delicate cutting of light weight materials such as paper, plastic, balsa, thin metal, cloth, film, and acetate. Includes a cap for extra safety. Replacement #11 blades are available. Knife handles also fits the No. 10, 12, 13, 16, and 17 blades.