of long-lived thermoplastic, Leviton Power Receptacles -- come equipped with heavy-gauge, double-wire copper alloy contacts. To ensure right and rapid wiring, terminals have markings. hot flash mount receptacles fit Leviton 's in breadth range of 2.15 '' - diameter wallplates and mounting hardware is. : Do not use with single-gang wallboxes, single-gang mud rings or single-gang box extenders.