The 3/4" BSPF Nut & 3/8" Barbed Elbow Adapter in Plastic with Washer is a plumbing fitting that is used to connect two pipes with different sizes or diameters. The 3/4" BSPF Nut is threaded to connect to a 3/4" BSP Female fitting, and the 3/8" barbed elbow is designed to fit onto 3/8" diameter tubing. The washer is included for a leak-proof seal. The adapter is made of plastic, making it lightweight, durable and resistant to corrosion. This fitting is commonly used in water and fluid systems in a variety of applications.