Manufactured from special cold-formed nickel steel. Each handle is designed to incorporate a satin finish, smooth loading and balance. Handles are stainless steel and non-sterile. Cincinnati Surgical Blade Handles are designed for use with Cincinnati Surgical Blades. It's important to ensure that the right blade is paired with the right handle. #8 handle (featured in the first photo, without the ruler)fits size 60 and 70 blades. (CS-B60, CS-B70). #4 handle, featured in the second photo, with a ruler on the handle, fits only size 22 blades. (CS-B22)