DOT Brass Air Brake Tube Tee Fitting. DOT Compliant. Tube Size: 1/2". Push To Connect. Air Brake Hose, Line, Coils. Air Brake Hose, Line,Coils. Proud ToServe. As we’ve grown, we have never ever cut corners, through launching our website in 2007, and moving our headquarters to Aurora, Ohio in 2014, we are dedicated to quality products and keeping the cost affordable.