Digital Engine Leak Down TesterDon't wait too long to rebuild that expensive motor BUT dont' do it to soon either. This easy to use tester checks ring seals, valves, even head gaskets. Much more accurate than traditional testers Reads critical leakdown to . 5% (1 2 of 1%) Gauges have back lights for easy readability and low battery indicators 14 mm hose comes with. 12mm is optional (52 73013) Control inlet valve avoids shock to gauges when air is turned on, allowing more accurate