U.S. Solid 2pcs Brass Pipe Fitting Adapter, Male Pipe x Female Pipe, 1/2" x 1/2", 1/2" x 3/4", 1/4"x 1/4", 1/4" x 3/8", 1/8" x 1/4", 1/8" x 1/8", 3/8" x 3/8" -
1/8-27 NPT Female to 3/8-18 NPT Male Thread Adapter for Pressure Gauge Sensor
Everbilt 1/2 in. Barb x 3/8 in. MIP Brass Adapter Fitting 800199 - The Home Depot