Pneumatic Connector T-Type Male Thread 1/2 Air 

It is designed for using to connect with polyethylene, nylon and PU tubing.

Tube Push Fitting Three Way Hose Pipe Quick Fitting Connector for Quick Connection of Air Piping (6 MM, 2)

Simple push in design for connecting to the tube and provide secure connection, requires no extra sealing.

Elliptical release ring on two ends facilitates pneumatic installations in confined spaces