Ok then I'll probably go to Home Depot and just for like a rally really close replica.... Also I'm not sure what part is what in the canister.
The trays can be used to arrange whatever you want in them. I don't know that particular filter so I am not sure if the flow is from the bottom up, or top down. Figure that out.
In your first picture those are ceramic rings used for bio filtration (i.e. for bacteria to grow on). They never (or rarely) get replaced once infested, you rinse them lightly if lots of crud and only rinse in tank water.
The second are bio balls which are plastic and have the same purpose, but are not very useful in canisters as they lack surface area. I'd recommend getting rid of those.
The third look like bags of activated carbon. Those need to go (unless they are new), and you may or may not want to replace them. Lots of people think they are wonderful, others think not so much. When new they will take tannins and organic matter out of the water often clearing up problems with organic stains (not so much anything else like algae or bacteria). But they only last a month or so, so if these are old, trash them.
I can't tell in the bottom but it looks like there's room there for physical media as well.
If this is a typical fish tank I'd do something like this (in order of where the water comes in first): find some sponge media, wide pores, stiff. This will filter the gross matter out coming through the filter. This also rarely needs changing, just rinse and ring it out in tank water, it also will house some bacteria.
I'd throw away the bio balls, and replace with either:
- More bio media, something like Seachem Matrix or the ceramic rings, or
- Fine sponge-like material, sometimes called "floss" which takes out more particulate matter. These tend to degrade over time, and need to be replaced every few months. Some people don't bother but if you have water cloudy from particulate matter it certainly helps.
Then if you want organic chemical filtering, either more carbon or purigen. I think the latter is better, it is pricy but can be recharged. NO chemical media lasts forever, you do need to replace or recharge every month or three (depending on how much crap in the water), so plan accordingly.
Then (still in order) the bio filter media, either one or two trays.
There are lots of variations on this, and it is really hard to do it "wrong". The idea is you have sponge-like stuff to take out particles, and if more than one kind stiff/porous first. Then chemical if you want it (or you can put these after bio, no big deal). Then bio. You always want bio media, and lots of it to make a home for the beneficial bacteria.
If adding this to an existing tank, do not remove your existing filter at first, leave both running for 2-3 weeks so the bacteria will infest the new. If you can't do that for some reason move a bunch of the media from your old filter into the new, and do regular ammonia/nitrite tests to make sure it took hold.
this is the top part 
2 part 
3 part 
and the last part which has nothin
