Eaton Weatherhead 60X6 Compression Sleeve, CA360 Brass, 3/8" Tube OD, 0.4700" Sleeve OD (Pack of 100) Sleeve for a tube compression fitting Connects to 3/8" copper, brass, aluminum, or plastic tubing Brass for corrosion resistance, ductility at high temperatures, and low magnetic permeability Operating temperature range of -65 to +250 degrees F No flaring tool required for assembly