Orbit UMAB-4R 4” (4O), 2-1/8” Deep Welded Octagon Box With Built-in Adapter, Adjustable From Flush to 1-1/2” 20 PackOrbit UMAB 4R UMAB 4R Product Description Orbit's Universal Mounting Adjustable 4" Octagon Box (UMAB 4R) is a fast, efficient way to install lighting fixtures, smoke detectors and devices where drywall depths are unknown. Built in adapter allows for adjustment of the 2 1 8 deep, 4O box from 0" to 1 1 2", ensuring devices and trims sit flush with wall surfaces. UMAB 4Rs mount direct to stud frames. Mount UMAB 4Rs between studs or joists with Orbit's