MAKITA BL4040F 40V Max XGT 4.0Ah High Output Battery miter saw protractor 10X Corrosion Resistance** Help Width:1 2 IN 10X Corrosion Resistance** Help minimize rust with a black chrome coating and nickel tip that provides protection Automatic Grade Matching basically means that the laser moves to the on grade position on the receiver and the grade is then calculated – this is generally used when a constant fall is desired but the grade may not be known (renewing existing driveways or matching existing surfaces) Rapid Charging: Reaches a full charge in approximately 45 minutes when used with the DC40RA Rapid Optimum Charger 0Ah High Output Battery (BL4040F)