Fotospeed Mono RA-4 is a product from Amaloco Photochemicals, the Netherlands.
It's very stable and has a tremendous long lifetime and can be also used in small developing machines till 27 degrees C in 2x30S (Thermaphot, Durst Printo). The only disadvantage compared to the the Rapido (33 degrees C) process is the amount of fall out of solid organics which gives more polution in the machine.
In trays it's the most simple way to get color prints processed.
K50/K54 and in Germany sold under Dilluprint Mono RA4.