4-PACK Humidifier Filters Compatible with Stadler Form Oskar Little, Oskar and Oskar big Evaporative Humidifiers.Such as O-020,O-021,O-022,O-025,O-026A,O-030,O-031,O-101,O-102,O-103,O-104 - Fre.Filtor

Not much to say here. Does what they need to do.

These filters are actually a better quality than Stadler Form filters I had purchased previously.I bought the 4 pack and got them for what 2 Stadler Form filters cost me.I will definitely buy all my filters from Fre Filter in the future

Perfect fit for Oskar humidifier

Filters are $10 to $15 cheaper than the Stadler Form brand ones, but after about a month of use it has made my Oskar start to smell bad, even though it is cleaned.

These are apparently off-brand filters. They are too large for my Oskar and create a gap in the fit of the top and bottom half of the humidifier. This in turns throws off whatever is sensing there is no water in the machine and causing the machine to turn off because it thinks there is no water, when in fact it is full.

Ordered these for my Oskar humidifier. They are less expensive than the Swiss style brand. They work just as effectively, but they were just a bit larger, so there is bit of awkwardness getting the top back on the humidifier after filling.

We used two of the filters. Both started to have black molds within one week of use!!

Mold within 1 week of use, don't buy this scam