Standard single-gang boxes that come with some new construction packages crack under pressure when you back-wire a receptacle, don't grip NM cable properly through the knockouts, and don't give you enough cubic inch capacity for modern devices - resulting in code violations on inspection. When you're running 12-gauge circuit wiring, the box fill matters, and you need a box that handles it. 18.3 cubic inch PVC single-gang nail-on box - the capacity for a single device with two 12-gauge conductors plus grounds, which is what most residential 20-amp circuits require. PVC body won't rust, lighter than steel for easier handling on tall runs, and the nail-on flange sets flush for a clean install on studs. Key Specs Capacity: 18.3 cubic inches - NEC-compliant for single device, two 12 AWG + groun Stocked at Crofton Lumber and Akron Lumber.