What we call a slip on is changing the whole muffler. Slip-on muffler. What you found is just something you add to your exhaust to make it look cool and heavier. It's like going to PepBoy and getting a chrome exhaust tip for your car.At the risk of sounding like an idiot, I don't understand.
In order to get a real slip on you either need to get a full exhaust like Two Brothers, or contact me.
Check out my website in my signature for more details.
Marthy