Milton S-653-2 - Brass Adapter 3/8" Fnpt X 1/4" Mnpt. Brass adapters are used to assemble new hoses or replace old fittings on hoses when reduction in pipe size is required. Brass is the best material to use for applications like this due to it's resistance to rust and corrosion like other metals. Adapter bushing Male one end and female on the other 3/8" Female NPT x 1/8" Male NPT Brass Skincard 0.