This device is a pneumatic fitting PU Series, 4mm port, used for air flow.
Specifications:
Material: PU
Fluid: air
Normal pressure range: 0-0.9Mpa
Maximum Pressure: 1.32Mpa
Low Pressure Range: -99.9~0Kpa
Temperature: 0 to 60°C
Fits Tubing OD:1/4''
Size: Approx. 35 x 13 x 13mm / 1.37 x 0.5 x 0.5inch
Weight: 66g