This is Echo's High-power 73.5 cc 2-stroke commercial grade engine with a 4-stage air cleaner system that results in longer air filter life. Decompression valve for easy starting. Automatic, adjustable clutch-driven bar oiler operates only when the chain is moving to reduce oil consumption. 19mm captive bar nuts – no chance of losing hardware, 3-point spring vibration reduction system for operator comfort. Aluminum handle with rubber grip for strength and comfort. Winter operation plug has 2 positions - 1 for winter and 1 for normal conditions - to improve engine operation