This combination elbow is made to adapt plastic pipe with a hose barb fitting to a male thread. These are commonly used in vacuum booster, manifolds, and canisters throughout a maple sap tubing system where a valve or other threaded fitting is needed. The aggressive hose barbs lock onto the plastic mainline tubing or black plastic water pipe, once it has been tightened down with a hose clamp, for a leak freehold. The standard male pipe thread (mpt) should be thread taped before use to ensure a leak-free seal. Using this elbow eliminates any pooling areas at the elbow because the fitting is molded smooth on the inside.