The Kaeser Compressor Oil Seal is a high-precision, heavy-duty sealing component engineered to prevent the leakage of Sigma Fluid lubricant from the air-end drive shaft. Specifically designed for the high rotational speeds and thermal stresses of the Sigma Profile™ rotary screw, these seals are typically manufactured from advanced materials like PTFE (Teflon) or high-grade fluorocarbon. Unlike standard industrial seals, genuine Kaeser oil seals are built to maintain a tight, friction-resistant barrier that protects the internal bearings from external dust while ensuring the air-end remains fully lubricated. Replacing this seal, often in conjunction with a matching wear sleeve, is a critical part of major air-end maintenance to prevent oil loss, maintain system pressure, and avoid the catastrophic mechanical failure that can result from a "dry" air-end.