Echo CS-4510 Rear Handle ChainsawMid size chain saw featuring more power, and lighter weight Features: 16" and 18" bars with 20BPX chain Automatic adjustable bar oiler allows adjustment of oil flow to match cutting conditions Momentary stop switch automatically returns to "on" position Spring assist starter reduces starting effort 3 point spring vibration reduction system provides operator comfort Choke with automatic fast idle for easy starting Dual post chain brake improves