This Mr. Gasket aluminum fuel block, Y-block, or junction block, is most commonly used when upgrading to multiple carburetors. It allows you to take a main feed line and T it out to two other outlets to those dual carbs. In addition, it has a 1/8 inch diameter port for a fuel pressure gauge. It could also be used for oil or water as well. Brass hose barb fittings and hose clamps are included, as are two screws and nuts to help install.