SMC KQ2S10-03S Hex Socket Connector, 10mm x 3/8 In. More details: Hex Socket Head Male Adapter, Basic Material Metal, Body Material Brass, Connection Type Tube x R(PT), Tube Size 10mm, Pipe Size 3/8 In., Max. Pressure 145 psi, Temp. Range 23 Degrees to 140 Degrees F