Just tried the filter.
I am guessing contains requires the whole string, I tried it for used equipment typing just part of one item and it could not find it.
I then went in to try more - entered the complete string and got nothing. Not sure what the behaviour should be (partial would be more useful) but I could not get it to work.
Numbers for size of cylinder worked fine though.
Beta version 5.0
Re: Beta version 5.0
used equipment does not work well for filters. Just the equipment ID's are stored, the equipment items are in a separate table and thus the filtering does not work here. Look at the UsedEquip field in the logbook table in edit mode. You see just numbers are stored, e.g. "5,2,10".