Which piece of equipment is used to attach two hoses with the same coupling connection?

The correct choice is an adapter. An adapter is specifically designed to connect two hoses that have the same coupling connection, allowing them to work together effectively. This piece of equipment ensures that hoses with fittings of the same size and type can be joined securely, making it an essential component in fire fighting operations where extended hose lines may be necessary.

In contrast, other options serve different purposes: a connector is primarily used to secure hoses but may not be suitable for those with identical couplings. A reducer is intended for connecting hoses of different diameters, allowing a smaller hose to connect to a larger one. Couplings are the fittings on the ends of hoses themselves, used to connect hoses to nozzles or hydrants, rather than connecting two hoses directly. Understanding these distinctions is vital for effective fire fighting and managing hose lines efficiently.