Non-metallic Adjustable Wall Boxes For both New and Old Work Residential Construction No Need To Remove Or Relocate Mounting Screws To Re-Position The Box Internal slots retain slider plate and guide it in a straight motion Internal steel/wood stud screws, 1/2" knockout Allied Moulded SB1 SliderBox Single Gang Adjustable Outlet Box - Internal steel/wood stud screws, 1/2" knockout. Volume (Cu. In.): 23.0. Depth (In.): 3-9/16. Width (In.): 2-5/16. Height (In.): 3-3/4. Material: thermoplastic. Test Spec: UL Listed per UL 514 C. Fire Rating Classification: 2-HR Wall & Ceiling.