I have some recent experience that may be helpful....

Short version: this exhaust fit perfectly on my 150cc GY6 TaoTao

Long Version:

Got a 2015 TaoTao AMT150-A from a guy on craigslist for a steal. It had only ~300km on it when I got it and the guy was practically giving it away at a price I just couldn't pass up.

4 weeks or so after bringing it home the flange that mounts the stock exhaust pipe to the engine snapped off during a ride. The crappy build quality of the scooter resulted in several of the exhaust's mounting bolts to get stripped and they loosened enough to allow too much play in the pipe whenever I'd hit a bump. Eventually this flexing caused it to break and I had to find a replacement...

I first bought this pipe and muffler set on Amazon for $79./

That was a mistake... The exhaust did not fit on my scooter right off, I had to bend the pipe an inch and a half by putting it in a vise and carefully heating it with a blow torch and bending the pipe to the correct angle. There was also a mounting bracket welded to the pipe that I had to cut off since it was angled such that it would have to go through the oil filler pipe on the side of the engine.

Once I got it on it looked and sounded great, plus I noticed a higher top end speed and overall better performance. That lasted for about 3 weeks until the weld where the lower bracket was attached to the pipe, right where the muffler bolts on, snapped off during a ride leaving a dime sized hole in the side of the exhaust.

I repaired the hole with some high temp fiberglass tape and repair putty, then fabricated a new bracket to clamp around this area and secure it to the frame. I was worried about how sound this would be but everything worked great for quite awhile.

Eventually though this failed as well when the entire muffler cracked off the pipe during another ride one night. At this point I gave up on this exhaust and went searching for another for a proper replacement.

At this point I did a bunch of searching and found this exhaust which has been absolutely perfect so far about 6 months in. It didn't require any modification to the pipe, bracket, or bike at all to mount it and is firm with no movement at all many months later. I did lose some of the performance increase that I got with the earlier exhaust but considering all the problems I had with that one I'm happy to accept that.

When I bought it I got it from Amazon but I can't seem to find it anywhere on there anymore, looks like the reseller that I got it from, Maxpro Llc, hasn't maintained their Amazon store front.

I can't vouch for other scooter models and styles but on my TaoTao this exhaust fit perfectly.