Middle Atlantic 880M3 Shallow Steel 3-Gang Floor Box
Overview
The Middle Atlantic 880M3 is a shallow-depth, steel-construction 3-gang floor box from the Omnibox Series, designed for in-floor power and AV connectivity installations where concrete slab depth is limited. At just 2.5 in (6.4 cm) tall with a 7 in wide × 13.75 in deep footprint, the 880M3 fits scenarios where a standard-depth box would breach the slab or interfere with subfloor structure — making it the right call for raised access floors, thin poured slabs, or retrofit installs in occupied commercial spaces. TAA compliance makes it eligible for federal, GSI, and government-funded facility projects without procurement complications.
Compatibility
The 880M3 is part of Middle Atlantic's Omnibox Series shallow steel floor box line. It is designed to accept standard 3-gang insert plates and Omnibox Series cover assemblies compatible with the shallow steel body. Verify insert and cover compatibility against the Omnibox Series shallow steel (concrete) product family — not all Omnibox inserts fit both shallow and standard-depth bodies interchangeably. Intended for concrete floor applications; not rated for wood subfloor or raised access floor tile cutouts without the appropriate adapter kit.
Installation Notes
The 880M3's 2.5 in height determines the minimum usable slab depth at the rough-in location — confirm pour depth before specifying. Shipping dimensions are 13.75 × 7.5 × 3.69 in, so plan staging accordingly in tight mechanical rooms. Concrete anchoring method and conduit entry configuration are governed by local electrical code and the installer's rough-in practice; no proprietary tool requirement is specified for the box itself.
