Bosch touts the small tool and head length (7" and 7.04", respectively) of its new PS31 Ultra-Compact Drill/Driver, along with the big impact of its 265 inch-pounds of torque. Weight? 2.1 pounds. The PS31 is part of Bosch’s lithium-ion 12V Max line, which changes the battery’s electronics from analog to digital and integrates an Electronic Cell and Motor Protection System to guard against overloading, overheating and deep discharging. The PS31 has a three-speed, single-sleeve, 20+1 clutch and a two-speed (0-350 rpm or 0-1,300 rpm) drive train. It sold for approximately $180 in 2010.