Ham-Let Stainless Steel 316 Let-Lok Compression Fitting, Adapter, 5/16" Tube OD Union for connecting and disconnecting two pipes more easily than couplings Fitting connects to tubing on both ends Type 316 stainless steel for higher strength and greater corrosion resistance than type 304 stainless steel Operating temperatures range from -100 to 1000 degrees F Meets ASTM standards A213 and A269 for quality assurance