A necessary part. You can't believe how many conversion kits it has taken to make this upgrade. Well, anyway the seller was no problem at all, arrived much earlier than expected. The part is clean, new and in perfect condition. I think the price is very good. I am installing this on a Yeti SB 66 with the upgrade being a Stans no Tubes wheelset. I built the bike myself, and I spent so much time riding the 575 that the SB is still mint. I went all Yeti 10 years ago.