Craft’s self-sealing brass couplings allow for charging the refrigeration, air conditioning, and heat pump systems without the use of traditional brazing. These couplings are extremely easy to use and are compatible with a wide range of refrigerants. Such as R410A, R448A, R449a, R513A, R134a, R407C and more… They range from 1/4” – 3/4”, and the connections are customizable to the core. UL listed.