1. Product Overview The 6307‑2RS1/C3 single row deep groove ball bearing is equipped with double-sided 2RS1 contact NBR rubber seals and C3 enlarged radial clearance. The expanded internal clearance compensates thermal expansion under long-term high-speed and high-temperature running to avoid bearing seizure. Double contact rubber seals effectively block dust, water mist and contaminants while retaining internal grease. Widely applied to high-temp heavy-duty industrial motors