I believe the "shock collars" are only for the Rage Extremes. The 2 inch still use the O-rings. I started using Rage 2 blades two years ago and have never had a bad thing to say. I love them. They have a new "chisel tip" that I may try this year. I am a little hesitant though. I have never had a problem with the originals and I am a believer in "if it ain't broke, don't fix it".