The Key Periosteal Elevator (3/4") is a surgical instrument designed for use in dental and orthopedic procedures. The "Key" refers to the specific style or brand of the periosteal elevator, while the "3/4"" indicates the width of the blade at the tip, which is 3/4 inch. This instrument is used to lift or separate the periosteum (the connective tissue that covers bones), providing access to the bone beneath.