Airflow regulating valves

Five or ten pieces of airflow control regulator valve.
It is made from plastic, and it is available in two colors.
Connect 4mm hoses on both sides and turn the valve to adjust the airflow.
 
 
Specifications
Material plastic
Color blue, or black
 
Size
Length 3.8cm and 1.5″
 
 
Notes
The real product colors may be slightly different from what you see in the images.
The product dimensions may be slightly different from what is written in the product specifications.