This accessory bolts onto the side of the spindle holder and has two stainless steel wound flexible hoses coming from it. One hose you connect to your compressed air supply (requires approx 2 bar pressure supply, so it's suitable for use with small compressors), the other hose you drop into your reservoir/container of water or diluted cutting fluid (this could be just be a simple drinks bottle used for cylists or a larger water butt container). The hose for the fluid has a small sponge filter at the end to avoid sucking up dirt or grit.
You can control the amount of spray expelled by twisting the nozzle at the end of the spray arm, which itself is adjustable for positioning, as shown in the image.
For the manual on/off control, you push/pull a small lever located ont he spray head assembly to turn it on/off. For the automated contro optionl, the spray coolant is switched on/off under software control (plugs into the second port at the back of the Zero3 controller box). The on/off commands come from the G-Code and will be switched on and off throughout the job any time when the cutting head is lifted out of the work and not cutting, during tool changes, and also when the job ends.