Hello Burnup, the evaporator cartridges for your Oskar are available in 3 different packaging units: 2-piece filter pack, 4-piece filter pack or, since recently, in an 8-piece filter pack. We wish you continued enjoyment with Oskar and will be happy to answer any questions you may have. Your Stadler Form Team

Stadler Form evaporator cassettes (set of 2) for Oskar

So the PM from Digitec fails here on the full line.
If the manufacturer has to answer questions himself.
Buy from microspot