The cartridge regulator has a dual purpose: (1) When pressed, it acts as an on/off valve and allows the water to flow. When released, it stops the water flow. (2) Once the water is flowing, the cartridge works as a regulator that controls how much water flows out of the bubbler head. It can be adjusted by turning the adjustment screw with a straight blade screwdriver.
This green spring cartridge is found in Elkay and Halsey Taylor drinking fountains with pushbar.
For drinking fountains with a pushbutton use item #102489.
The red and green cartridges can be used interchangeably. The only difference is the tension of the spring. The green spring has more tension.