ECHO CS-501P-20 Chain Saw 20" Bar Rear Handle Professional 50.2cc EngineECHO CS 501P 20 Chain Saw 20" Bar Rear Handle Professional 50. 2cc Engine 20% more power than the CS 490 with more professional features Features: 50. 2 cc professional grade, 2 stroke engine Captive bar nuts no chance of losing fasteners Ergonomic aluminum front handle for improved comfort and maneuverability Professional grade bar and chain for maximum cutting performance and durability Automatic, adjustable clutch driven oiler reduces oil