One of the first corded electric chainsaws on the market with a chain that can sharpen itself - perfect for DIYers and homeowners Built-in PowerSharp self-sharpening system minimizes downtime by allowing you to sharpen your chain on the saw in 3 to 5 seconds Long-lasting 18-inch (45 cm) guide bar with built-in Lubri-Tec automatic oiling system, for longer lasting bar and chain Tool-less tensioning system included; simply turn the convenient red knob to tension the chain No assembly required; chainsaw comes pre-assembled