Horizontal screw-down mounting, 10Mm, white with black, lamp base Gx23, gx23-2 - lamp holder for Gx23 and gx23-2 lamp bases - 547020 - manufacturer part number: 26720-200 - manufacturer: Leviton
GX23, GX23-2 Base, 2-Pin, Compact Fluorescent Lampholder, Horizontal, Screw-Down, Black Color Code, Quick-Connect 18AWG Solid or Str, Tinned, White Body