GR Type Conduit Outlet Box, Explosion-Proof, Dust-Ignitionproof, Malleable Iron, Unilet, GRX Hub Type. Includes: Internal Ground Screw and O-Ring, Internally Threaded Surface Cover with 3.88" Opening, 18 Cubic Inches and (4) 3/4" Threaded Hubs. For use with Threaded Metal Conduit.
- Material: Malleable Iron
- Diameter: 3/4 in
- Cubic Inches: 18 in³