Non-Metallic Boxes & Covers

Three Gang Non-Metallic Romex Box - 57 Cu. In. p-MSB3G MSB3G

Southwire #: MSB3G Model #: MSB3G

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MSB3G 3 GANG DEVICE BOX 57 CU IN

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Three Gang Non-Metallic Romex Box - 57 Cu. In.

Features & Benefits

One-piece, thick wall molded construction for stability and rigidity
Wire entrance clamps on top of bottom of box
Mounts to wood wood or metal studs 25g.
6-32 threaded device holes
42 lbs. mounting screws provided
UL Classified for 2-hour fire wall
UL Listed & RoHS Compliant

Specifications

Model #	MSB3G MSB3G
UPC #	784297017650 784297017650
Product Height	3.81 9.68	inch cm
Product Width	6.02 15.29	inch cm
Depth	3.26 8.28	inch cm
Product Weight	0.588 0.27	lbs kg
Material	PVC PVC
Cubic Capacity	57.0 (934.1) 57.0 (934.1)
Standard Package	8 8

Resources

SmartBox™ Information

Smartbox Booklet

REC Line Card

Rated 1 out of 5 by Elicia from Useless for three 20A receptacles/outlets I wanted to use this box for three 3-way switches on a 20 amp circuit. That means for each switch I need to be able to run in one 12/2 cable and one 12/2 cable. This means that since the box only has two 12 AWG V-notches (N #12) and four 14 AWG V-notches (N #14) it cannot support three 12 AWG switches or even three 12 AWG outlets. Which makes it useless. Why have three gangs when you can only support two switches or receptacles on a 20 amp circuit. I don’t care if it says it has the room. It doesn’t have the correct V-notches. The notches also break off. when inserting two 12 AWG NM B wires, leaving a big hole.

Date published: 2026-09-12