Manual controller with high horsepower rating of 20 HP. Compact design. Gull-wing shaped brass terminal pressure clamps. Constructed of glass-reinforced thermoplastic. Two-point contact arms. One-piece contact carrier. UL508 and cULus Listing of individual device and assembled device within enclosure. Heavy-duty zinc-plated steel strap. Two brass rivets secure strap to housing. External screw-pressure-plate back and side wire terminal screws unstaked for use with ring terminals. Oversized silver alloy contacts. 2-3/4 inch hubs (7812-EX and 7813-EX). 2-1/2 inch knockouts on back and 2-1/2 inch -3/4 inch knockouts on top and bottom. 2-1/2 inch knockouts on bottom and back.