Ball bearings are available with different types of shields and seals. Bearing closure can extend the bearing life by preventing contaminants from reaching the critical surface inside the bearing.

ZZ pressed metal shield drawing

ZZ: pressed steel shield

non-removable
non-contact
no increased torque
shields material on stainless steel bearings are AISI 300 sereis stainless steel
Z means single shield.

2RS contact rubber seals drawing

2RS: contact rubber seals

removable
greatly increased torque
greatly reduce lubricant leakage
reduce the max. speed of a bearing
RS means single seal.

2RU non-contact rubber seal drawing

2RU: non-contact rubber seals

removable
no increased torque
high speed

ZZS metal shields with snap ring drawing

ZZS: steel shield with snap ring

removable
non-contact
no increased torque
shields material on stainless steel bearings are AISI 300 sereis stainless steel

TTS teflon seal with snap ring drawing

TTS: teflon seal with snap ring

removable
increased torque
reduce the max. speed of a bearing
excellent chemical resistance