The LH0025 HH Fluorescent 1-526SW is a lamp holder socket that is non-shunted and is for  T8, T10, T12, G13 medium bipin base fluorescent lamps. It is a slide on "V" lock tombstone, socket for 20 gauge or less fixtures, 660w-600v, and 30.2mm lamp axis. It is also cULus and CSA ...