The bosch gsr 18 v ec te professional cordless drywall screwdriver has the best combination of power and weight it has the longest runtime for continuous work up to 3400 screws per battery charge with 40 ah a compact design and light weight for fatigue free work ndash 16 kg 40 ah there is bosch ec motor technology for long lifetime and it has the shortest head length 207 mm for precise work there is a locking button for continuous and fatigue free work and an integrated led light