This 51 in 1 small electric screwdriver has a 300 rotating speed per minute, automatic/manual mode with 0.4-0.5 N.m torque, battery capacity is 350 mAh, charging time is less than 70 minutes, standby for 30 days. Also, it can work continuously for 1 hour, which is completely enough for tighten a total of 400 screws. Product size only 22.3*10.7*24mm, weight only 1 pound, lightweight, portable, and easy to carry