The Sub-Compact 6-1/2? Circular Saw has a compact and ergonomic design at only 10-5/8? and 6.4 lbs. (with 18V LXT Compact 2.0Ah battery, battery and charger sold separately). The compact size combined with the Makita-built brushless motor delivers up to 5,000 RPM and a superior power-to-weight ratio. The saw is equipped with Makita?s Automatic Speed Change? technology, which adjusts cutting speed and torque under load for optimum cutting performance. The efficient brushless motor is electronically controlled to provide up to 50% longer run time than non-brushless motors, and in run-time testing the XSH04 made up to 174 cross-cuts per charge in 2x10 SPF lumber using one 5.0Ah battery (sold separately). For extended run time users can load up a high amp-hour 18V LXT battery (all sold separately) including 2.0Ah (BL1820B), 3.0Ah (BL1830B), 4.0Ah (BL1840B), 5.0Ah (BL1850B) or 6.0Ah (BL1860B).