This corrosion-resistant stainless steel coupler has a 3/8-24 female inverted flare (convex seat) port at each end. It is perfect for connecting two pieces of 3/16" hard line (not included). Sold individually.
Note: Although the 3/8-24 thread size matches the 3AN thread, this union does not have the correct internal seat to accept 3AN male fittings.