Amazon.com: Horiznext npt 1/2 female thread stainless steel tee pipe fitting, three way 3/4 inch I.D. connector, metal cast t shaped adapter for water air furniture tank tube industrial (1 pc) :
Tee Fittings - Bronze, NPT
RELIABILT 1/2-in x 1/2-in x 3/8-in Galvanized Reducing Tee in the Galvanized Pipe & Fittings department at Lowes.com