I used these to repair my 2 year old Pentair pump. The original bearings only lasted 2 years. Well it's a joke. My old pump bearings lasted 20 years and were still very quiet. The spa guy wanted to put in a new $750 pump. I bought a seal kit and pulled the pump out, put it on my stand, installed new bearings, seals and gaskets. It cost me $30 and a full day of handwork, which I love. A year has passed and the pump is silent. Advice. Stay away from cheap Chinese bearings. Spend a few bucks more on good USA bearings and save yourself the trouble of having to repeatedly rebuild your motor due to using cheap bearings.