You are purchasing one each Parker compression male connector, P/N 68C-6-4 for 3/8" tube by 1/4 male npt. Material is brass. Please look at our other listings for more Parker, Swagelok and Nupro instrumentation fittings. We will combine purchases to save the buyer on shipping. If you are purchasing multiple items and the shipping charges look wrong, they probably are. Please ask for an accurate quote We refund excess shipping charges.