The purpose of the common rail oil return detection tool is to measure the return flow of the high pressure diesel injector. The measuring box can simultaneously measure the return flow of all 6 injectors by comparing the return flow of each injector to the tank. Features: This set of tools is for measuring the amount of fuel the injectors return to the deposit tank, and it can be used to identify damaged or clogged injectors. This Oil Flow Test Meter Set can measure up to 6 injectors simultaneously. Direct measurement of return flow of the injector. Easy to use and install. Six measuring cups, each with a 70cm tube for more accurate evaluation. Measurement of return flow using external flow meter. Specifications: Case color: red Package size: 375 * 270 * 75mm / 14.8 * 10.6 * 3.0in Package weight: 1366g Package list: 6 * Adapter: for Bosch injectors 6 * Adapter: for Siemens injectors 6 * Adapter: for Delphi injectors 6 * Adapter: for Denso-injectors 6 * fuel-resistant transparent hoses 6 * graduated reservoir bottles for use when running engine (capacity of 105 ml) 6 * graduated manometer tubes for use when cranking engine (capacity of 95 ml)