BLACK+DECKER LCC420 20V Lithium Ion String Trimmer and Sweeper Combo Kit 20-Volt MAX Lithium Ion battery has a longer lifespan and retains its charge 5X more than NiCad String Trimmer features an transmission that delivers more cutting power Trimmer easily converts to edger to cut along sidewalks and driveways The Automatic Feed Spool ensures continuous work without bumping and having to stop to adjust Sweeper is light and powerful and easily clears debris from hard surfaces