18" (46 mm), 36" (91 mm), 48" (122 mm) nominal stem lengths 3/4" (19 mm) NPT, 150# or 300# ANSI RF flanged sockets 100 Ohm copper or DIN platinum non-inductive wound resistor Type 304 stainless steel sockets 0.25" (6.4 mm) standard bulb diameter Explosion proof aluminum junction box with terminal strip Other sizes available and configurations optionally available