I bought these to put in my Vance & Hines Straighshots with standard baffles. I had to simply cut them to size with scissors. The original factory repacking material was about one inch to short in length and half inch to short in making a complete wrap around the baffle. With this repacking material made for the quiet baffle it seems to mellow out the sound when the RPM's are low 3000 or less. At least enough I don't hear the exhaust in my sleep anymore after a ling ride.
Also the description says it is enough material for one muffler but it is really enough for one exhaust system. So now I have an extra set.
I have the Vance and Hines true duals on my 2009 H-D Roadking. One package per muffler fit perfect and took the crackle out of the sound and made for a much more mellow sound. I found the best deal from Dennis Kirk and it shipped the same day. Best service ever!
I think V&H sells this just to get extra money. The original baffles do not have a thinner area to put fiberglass rap around so you have to use these. They are shorter than the stock baffles. The rap or these are thinner than the additional rap you can buy on here. I took the rap off and put the new rap I bought here around the area. My Straight Shoots are acceptable in sound now. I think I should have stayed with the stock pipes.
Installation into exhaust pipe after wrapping quiet baffle was difficult. I ended up wrapping scotch taper around the fiberglass to keep it in place during installation into the exhaust pipe. Better installation instructions are needed.