The Allstar Engine Oil Pressure Primer Tank supplies initial oil to the oil pump in engines equipped with a crank driven oil pump. Operation is easy, just fill the 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. Features include a fill cap with safety pressure release slot with an o-ring seal, 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.