Instruction: Generate an answer to the question by utilizing the information contained in the document.

Input:
Question: What material are the grill plates made of? Aluminum/other metal or plastic?
Document: Those plates (grill plates) don't come off, so, you will have to get a sturdy brush if all goes wrong. Follow the instructions and you'll be fine:)
My initial impression when I unboxed this waffle maker was "wow, this thing is lighter than I expected and that's a lot of plastic." The design is good and the idea is sound. However, I'm a bit dubious of the materials and build quality. What metal there is (and there isn't much) is thin and flimsy.
Love it, keeps my paleo waffles crispy crunchy on the outside--both sides--and moist n fluffy on the inside. As stated in other reviews, the outside gets very very hot--but what do you expect eh? Treat it like you would any cooking appliance, us the plastic handles and don't touch the metal parts earn it's in use--duh.
The waffle nonstick grill is easy to wipe clean but if any batter spills over and gets into the crevasse along the ring, it is harder to get clean. I don't like the plastic handle as it is not very strong and can and probably will break someday. Also you need to really watch your waffle and use a trial and error for the first few times to see how long it takes to make your perfect waffle.
One waffle was enough for me.Only thing I dislike is that when closed, the two halves of the handle do not seem to be tight together. Maybe that's on purpose to ensure the metal griddles(?) touch each other instead of the handles hitting first instead.To store it upright, there is a U-shaped plastic piece which rotates upwards and holds the two halves together...it does not hold the halves tightly together and doesn't seem super reliable.
My Presto waffle iron heats up extra hot on the left-hand iron plate, and just right on the other side. So, when I make my waffles, I have to start out on the left, leave it for half as long as I would expect, then flip it quickly or it blackens the ridges of the waffle.It's a bit of a pain to clean since it's got deep extra narrow grooves in the plastic edge around the iron plates.
The trick to excellent Belgian waffles is they need to be flipped. However you do not need a professional looking one that the restaurants have. Those are large heavy metal units that last forever. The ones they sell to the public are large but made cheaply. The Presto is small and fits in a kitchen cabinet. It also flips but uses your countertop to support it. Simple yet it works. Also there is no on-off switch. Who needs one.
The first 2 batches of waffles I made with this iron, turned out rough. They were different recipes, and they involved beating the egg whites to a meringue type consistency. Each time, I saturated the grills with oil, but both batches stuck horribly. I poured the batter in the center of the grill, and it stuck so bad I had to turn the waffle iron off to get the waffle out, and it was impossible to get it out in one whole piece.
I'm a guy. I'm not a good cook. A large portion of the stuff I make I wouldn't even classify as cooking. That's why I like simple devices that work well. The greatest cooking device ever made was the microwave. The second might be the foreman grill. I've owned the same foreman grill for almost ten years and it still works great. There are fancier grills out there, but they are marginally better and magnitudes more expensive.That's how I view this waffle maker.
The unit worked well for about a year when it failed - the electrical wire between the two plates broke. Typical of crap made in China. It's no wonder the landfills are filling up so rapidly.
Answer: They are made of metal, not sure which metal. They are also coated in a non-stick coating.