The Penguin Refillable Media Cartridges are better than media bags, the patented ribbed design keeps the media of choice evenly distributed for maximum water-to-media contact, and the snap open and lock tight design ensures no media spillage.
Awesome Product by ItchyNissan from Federal way wa01/07/2012
I purchased this product so I would not have to buy the ones that are not refillable. I purchased 2 because I noticed 2 slots in the penguin 200 filter. The filter cartridge is great. It's sturdy, holds a lot of media and fits perfectly. The price was awesome and the shipping was really fast. I purchased them and got them on the 2nd or 3rd day. I can't remember but I think it was the second day. Great company to buy from. I was satisfied and you will be to.