yeah I think its the penguin filter, I got one on accident and they looked exactly like that one, don't know what size tho. Cascade might work too. The issue with those walmart things is they don't have any biological material and with only one filter when u change it ur replacing everything, most HOB
filter at least have a bio sponge or something that you leave in there, and there is no way to remove the carbon for medicinal treatments. The Fluval's have a separate wet rack with bio material and a separate filter and carbon try, so do aquaclears but I find the little bags a PITA.