This screwdriver set  operates at 175 RPM with 0.3 N.m torque in electric mode and 3 N.m in manual mode. It features a magnetic case with a built-in magnetizer/demagnetizer for easy bit magnetism adjustment. Powered by a 3.7V 350mAh lithium-ion battery, it can tighten up to 410 screws on a full charge. Price drops from $39.99 to $19.99 with code "T48C9X8N". Shipping is free with prime.