Expansion Coupling, 3-1/2″, Steel for Dry Locations
https://testing.nsiindustries.com/product/expansion-coupling-3-1-2-steel-for-dry-locations/
The Bridgeport 3-1/2″ Mighty-Move Zinc-Plated Steel Expansion Coupling is used to compensate a plus or minus 2-inch lateral movement for rigid or EMT applications in dry locations.