Model DHS680 is a 165mm (6-1/2 ) Cordless circular saw powered by 18V Li-ion battery. The DHS680 boasts a no load speed of 5000rpm compared to the DSS611 and DSS610 that sit at 3700rpm. Features of the Makita DHS680Z include: Automatic Speed Control: Automatically changes the cutting speed according to load condition for optimum operation. Electric brake. Soft start. Electronic current limiter for overload protection. Tool Hanger. Twin LED job light. Battery fuel gauge. Rear dust exhaust port. Large lock off lever. Compact and lightweight design. Ergonomic soft grip. Blower function to clear wood dust from cutting line. Larger base than current models for more stable operation. Makitas New Lithium Ion Brushless BL Motors Makitas new Brushless Motors give up .