These molded vinyl cups come in 2-inch and 2 3/4-inch diameters to fit small and large tubes, and each is fitted with a 3/8-inch hose barb at the bottom. The fit is tight, so warm the vinyl in the sun ...

Barb fittings create a better seal on a slightly softer hose, while push-quick fittings are easier to use with a stiffer hose. For example, Clippard recommends using 85A durometer polyurethane ...