Orbit SSBT-4R Preassembled SSB-TBAR With UMAB-4R 20 PackOrbit SSBT 4R SSBT 4R Product Description Orbit's Preassembled SSB TBAR with UMAB 4R is a fast, efficient way to install lighting fixtures in drop ceilings where tile depths are unknown. The bracket adjusts from 15" to 25" to span the T grid, and includes riveted clips that snap easily into grid channel. Bracket stays rigid to prevent downward pressure on ceiling tiles, even at full extension. UMAB 4R's built in adapter allows for vertical adjustment