Primer tank supplies initial oil to the oil pump in engines equipped with a crank driven oil pump. Fill primer tank with engine oil then apply compressed air to force the fluid throughout the engine via the oil pressure sender/switch port to pre-lube the entire engine including the oil pump. Tank features include a fill cap with safety pressure release slot (sealed by o-ring), an easy to read pressure gauge and a quarter turn on/off supply valve. The oil supply line is a durable 90" long steel braided hose with -4AN ends and includes a fitting with male 1/8"-27NPT threads. Adapter fittings sold separately.