Instruction: Output yes if the supporting document can answer the given question. Otherwise, output no.

Input:
Question: Can those snap rings of different size be bought separately?
Document: Good quality , nice size.The different sized rings are easy to remove and replace.Starter pin fits securely. Be sure to center your router's base.
I like the base. I have a hitachi m12v mounted to it. No flex whatsoever in the plate. It is very rigid and does not bow. The included hardware is good, but I did not care much for the nylon raisers. I bought #10 24-thread , machine screws to replace these. Just a preference, not mandatory. Comes with a start pin for table routing smaller piece with no fence.The snap in rings are strong and rigid. They snap in real tight.
Great router plate. No matter what everyone says, if you can follow instructions you can mount this plate with dead-on accuracy. I bought the centering system designed by Rousseau for $6 and I would recommend you purchase this accessory as well. It made it a snap to install. The plate is machined well and fits perfectly. The 'snugging' corners work well and provide a solid secure fit. The center rings are not a problem to snap in or out.
Wanted another base for another router so I wouldn't have to switch routers on same base. Bought one just like it about 15 years ago and was still performing ok. Also the 9x12 size is somewhat unique so needed same size as before. Only issue is the rings don't pop out particularly easy. Sometimes when trying to get inner ring out outer ring comes with it, but it's no big deal. Seems to be strong enuf. Have had no issues with sag.
Needless to say, I returned it. I purchased a very nice machined 1/4" aluminum plate from Rockler instead that it IS flat, and has an very nice anodized coating. It works excellent! I highly recommend that you save yourself the time and money I lost and do the same. Keep in mind that the aluminum plates also have different sized inserts you can buy or you can get a solid one that you can drill out for a custom size.
This router plate is sturdy and well thought out. The snugging corner pieces cleverly and solidly hold the plate without fastening it. The rings securely snap into the plate. A spare outer (red) ring should be provided since it is the one likely to be enlarged to safely accommodate large bits.
Spend the extra cash and get an aluminum plate with quality snap in rings. Also Rousseau's customer service is a nightmare. This has a lifetime warrantee so I called to get get a free replacement after I broke it. 3 months and numerous phone calls later I FINALLY got a new one from them  ... with the same stupid problem.
I just ordered and have installed one of these plates in the router table I am building. Before ordering this model, I was somewhat concerned after reading the other online reviews but went ahead and took the chance. My plate was easy to install and mount my router to. The snap in rings are not the easiest to get in and out but on the other hand I don't want them popping out on their own. It is a sturdy plate and the installation instructions were easy to follow.
I have used this plate for 2 years now and it stinks. The crown in the plate is ok ... I don't mind that, but the snap in rings are a bear. You have to use a hammer and hit it hard to snap them in and out. Last night I was hammering them out and the whole plate shattered. Now looking at Rousseau's higher quality router lift I find that it has the exact same plastic top and the exact same snap in rings.
A gentle tap, and they pop. Ever see the commercial with the guy fighting to get the lid off of the jar, and the wife comes over, gives it a light tap, and pry's it right off. This is the same thing, albeit a slightly different principle.Forget setting it up using the concentric rings on the bottom of the plate. The porter cable template guide should be your guide. The beauty of this Rousseau plate is that you can use it for freehand, and template guided work.
Answer: yes