Single-phase, Three-wire, 120/240 VAC. Convertible. Split neutrals extend the full length of the interior for ease of wiring. Removable closing cap. Minimum 100 percent neutral terminations. Sturdy copper bus and galvanized box. Combination slotted/Robertson screws. All holes are rated for 14-4 wire. Maximum of four 1/2 inch spaces. UL listed.