Hi all. Getting ready to do the mod on my Revo 3.3. So I ended up cutting enough rings to do 8 Revo's. Im keeping a set but anyone who wants a set for there revo PM me and Ill send them to ya. Just send a self stamped,with addressed envelope,, in another envelope and i'll get them out to ya. Ill answer 7 PM's and let you know if your picked. There copper rings that just need a small amount of filing or Dremel on inside edge to fit. I got bored at work the other night and ended up cutting the whole copper pipe down.