The LH0010 (HH 1-500W-C) is a G13 medium bipin socket. This lamp holder is non-shunted, butt-on mounted and has 9 inch leads.The LH0010 is comparable or equal to the American DeRosa  D2653, DM Y68L, 85862, HH Fluorescent  1-500W-C, Leviton 395-W and the Triboro: 637-A. Link to T8, ...