What is the difference between Master LM2/Master Pro P1 and P2, look the same in appearance?

Main difference between both models is the cleaning system.  LM2 P1 and Master Pro P1 are with one peristaltic pump for measuring system, while LM2 P2 and Master Pro P2 are with two peristaltic pumps – one for the measuring system and another for the cleaning system, allowing P2 to be automatically cleaned without operator intervention