The Leviton 9878 is a keyless, single-piece, glazed white porcelain sign socket with a medium (E26) base, designed for 660W/250V-600V applications. It features center mounting with two #8-32 flange/bushing connections, a screw shell, and is commonly used in commercial lighting, such as channel letters or signs. It is similar or equal to the Satco 80-1149