When your flexible hose line needs to marry a threaded port of a different diameter, this 3/8 in barb to 1/4 in NPT male adapter solves the mismatch cleanly. The 3/8 in barbed stem pushes into the hose interior and locks in place under pressure, while the 1/4 in male NPT tapered thread screws into pumps, valves, manifolds, and other threaded equipment ports for a seal tighter than straight-thread alternatives. Solid brass construction ensures the fitting handles water, fuel, and compressed air applications without corroding or deforming over time. At just 2 x 1.5 x 0.75 in per piece, these fittings install in tight engine bays, filter housings, and equipment panels where bulkier couplers would not fit.