http://pastport.jp/user/bearingsupplier/timeline/Deep%20Groove%20Ball%20Bearing%20Suppliers This causes an issue of run out and this problem increases for long shafts. So why do you need mixer seals? These seals are used to basically Wholesale Series 16000 & 6700 Deep Groove Ball Bearing Suppliers mix and agitate the contents in shafts ,vessels. ja-JP