The only link online i can find is. Liquid cooled water and corrosion inhibitor mix which will probably need changing.
I have run it from time to time, checking the inside the belt seems good with no leaks anywhere but i never did get an air rifle to to test it fully. Comes with instructions, see picture for specs. Im sure it can be used for scuba but not entirely sure. The item "200bar, 18L per min, 230v, water cooled Air rifle/scuba air compressor" is in sale since Wednesday, August 5, 2020.This item is in the category "Business, Office & Industrial\Hydraulics, Pneumatics, Pumps & Plumbing\Pumps & Pump Accessories\Other Pumps". The seller is "derek23cat" and is located in Margate . This item can't be shipped, the buyer must pick up the item.