They're a throw away item. The filter has a bypass in it ..and a large washer magnet (it matches the end of the filter). I believe that these flow inside to outside. It looks just like a miniature cartridge filter inside ..with mesh reinforcement on the exterior.
My first one was installed a long time back (pre-BITOG) when I had my trans serviced. When I went back to the same guy (still pre-BITOG) he said that he probably wouldn't change it. He didn't.
They apparently sell a ultra trick version of it ..but I don't know the details. It's very expensive. If you have the room, install a spin-on hydraulic filter and mount.
They surely aren't what you call "cheap" ..but they do allow any autotrans, regardless of space limitations, to get the benefits of auxillary filtration.