This .100 jet is used when you just have to much water flow going to your headers. Can be drilled out to larger size. This jet will limit flow. The jet is installed by threading into pre-threaded Hardin Tee Valve.
Note: This is designed to fit Late Model Hardin Marine Pressure Tee Valve, otherwise you will have to drill and tap your fitting to accommodate. 7/16"-28 Thread. The Hardin tee value uses 2 of these, they are Sold Each, NOTE Photo is not the exact product, just an approximation.