Confused by "but" phrase in this sentence

I'm translating a product leaflet into my native language, and have a problem with the following sentence:

"ABC's compact Probe-65 is an excellent choice when your application calls for turbidity monitoring, but only a few additional sensors."

I'm afraid I don't fully understand a meaning of but phrase in this context. Could anyone clarify it for me? Any help will be appreciated. Regards,

"but" effectively means "and" here, like saying:

"ABC's compact Probe-65 is an excellent choice when your application calls for turbidity monitoring, and only a few additional sensors."

"But" generally tells us that something unexpected is happening, or something that contrasts with what we were told earlier. "He normally walks to work but that day he got the bus" for example.

The "but" draws attention to the fact that there's an unexpectedly small number of additional sensors (which presumably makes it cheaper or something) - there's an implication that if you want turbidity monitoring you would normally have to have a lot of additional sensors, so the 'but' draws the reader's attention to the fact that there are less additional sensors than you would expect.