Midland Metal 20058 Straight Connector, 3/8 in Tube OD x 1/4 in Male NPTF, Brass

Male Adapter, Connection Size 1: 3/8 in, Connection Type 1: Push-to-Connect, Connection Size 2: 1/4 in, Connection Type 2: Male NPTF, Brass, 3/8-18 x 1/4-18 Thread, 0.56 in Hex, 1.11 in L, -10 to 200 deg F