The object in the image is a number 3 surgical scalpel handle. This handle is also called a Bard-Parker (B.P.) handle. The company patented the two-piece scalpel design in 1915. The handle is reusable and made of stainless steel. It has a slot at the tip to attach single-use blades. 

• Design: The number 3 handle is flat with horizontal serrations for a firm grip. It is used for cutting gingival tissue and making surgical incisions. The handle is held with a fingertip grip. It is a versatile tool for different surgical procedures.
• Dimensions: A standard number 3 handle is about 13 cm (5.1 inches) long.
• Compatible Blades: The number 3 handle works with various scalpel blades, such as sizes #10, #11, and #15. Other compatible blades include sizes 6, 9, 11P, 12, 12D, 13, 14, 16, and 40.
• Applications: This type of scalpel handle is used in general surgery and fields such as podiatry, veterinary medicine, taxidermy, and crafting.