Middle Atlantic STL DP FLR BX 3-GANG Ombx - 880S3

Middle Atlantic 880S3 Steel 3-Gang Concrete Floor Box

Overview

The Middle Atlantic 880S3 is a steel, 3-gang floor box designed for in-concrete installation where you need to bring power, data, or AV connections up through a slab. At 7" wide × 3.5" tall × 13.75" deep, the 880S3 drops into a concrete pour or cut-in application and provides three gangs of device space — enough to accommodate a combination of duplex receptacles, keystone data inserts, or AV connection plates without crowding. TAA compliance makes it viable for federal facilities, government buildouts, and GSA-schedule projects where domestic sourcing requirements apply. If you're routing cabling infrastructure through a raised or poured concrete floor in a conference room, operations center, or public space, this box addresses the structural and regulatory requirements in one housing.

Compatibility

The 880S3 is part of Middle Atlantic's Omnibox series of steel floor boxes. It accepts standard 3-gang wall plate devices and keystone inserts following conventional gang-box sizing, making it compatible with a wide range of power, data, and multimedia connectivity modules from Middle Atlantic and third-party suppliers that conform to standard gang dimensions. Verify device plate width and screw-pattern compatibility with your specific inserts before ordering — 3-gang boxes vary slightly by manufacturer in their device rail spacing. Pair with Middle Atlantic's Middle Atlantic structured cabling and AV infrastructure line for a matched system, or integrate with compatible floor boxes and cable management products for complete in-slab pathway solutions.

Installation Notes

The 13.75" depth requires adequate slab thickness or sub-floor clearance — confirm pour depth or cavity height before specifying this box. Installation is intended for concrete floors; verify local code requirements for flush floor-box applications in occupied spaces. TAA compliance is verified for the 880S3 SKU, making it suitable for projects requiring TAA-compliant infrastructure components.