Power Team® hand pumps, with the angled fill port, have a built in relief valve protection system. This system is designed to protect over pressurization of the reservoir from sudden back pressure. This system also works as a seal to prevent oil leaks. Power Team® Hydraulic Hand Pump, 2-Speed Manual, Series: P, 55 cu-in Tank, Oil Fluid, 325 to 10000 psi, 3/8 in NPTF, 23 in Overall Length, 4-3/4 in Overall Width, 7 in Overall Height