Got this for my 2021 SSR125 and it topok maybe 30 minutes at the most to install. Was very easy besides having to use the stock nut and bolt for the silencer hanger but bike is much quieter more comparable to a CRF50/110 but with a deeper tone. The bike also feels more smooth and runnability was improved. Haven't noticed a drop in power it can just be deceiving because it is quieter so you think its less power but if anything the low end feels improved.
Best exhaust system for the SSR out of all the units I have seen. Highly recommend.