The DE-200 is a semicircular desk corner filler for L shaped desks. The circular part of the DE200 is installed in the "L" and creates up to 65 square inches of additional surface space. Self-tapping screws make for quick and easy installation. The DE200 is about 16.25" long and about 8.5" wide, and is designed for L shaped (or double L) desks that are about 1" to 1.25" thick.