Adapter to winterize underground irrigation sprinkler systems. Includes most common pipe thread combinations! Avoid multiple trips to the hardware stores. Pressure rating: 250 psi. All metal parts are lead-free brass. 100% outdoor rated. Impervious to water and oil. One end of the adapter has a quick-connect plug designed to connect to most air compressors. The other end can be customized into five Male National Pipe Thread (MNPT) connections (1/4" MNPT, 3/8" MNPT, 1/2" MNPT, 3/4" MNPT, and 1" MNPT) and three Female National Pipe Thread (FNPT) connections (1/2" FNPT, 3/4" FNPT, and 1" FNPT,) to fit most home underground sprinkler systems.