20-Piece Set Of Craftsman Cmht66718B20 4V Screwdrivers. The CRAFTSMAN 4V Screwdriver delivers simple push button, power assisted speed in one of the most compact integral battery designs available. The 300 RPM (no load) motor drives screws 4x times faster than a standard fixed screwdriver making it perfect for free run, low-torque applications including electronics repair and installing switch plates. When additional powered is required, the motor engages an automatic spindle lock that stabilizes and protects the gears for manual torqueing. The 1.5Ah li-ion battery offers long-lasting reliability, with USB charging and 3 stage LED battery status indication. LED lights activate automatically when in-use improving visibility to working surface. The set includes (6) 1? bits and (1) bit extension for added length, and a quick change locking collet for reliable hold and simple changeover of bits. **Drives scews up to 4x Faster No-load 300 RPM for high speed driving Ideal for free-run or mechanical screwdriving. Rechargeble Integrated 4V Max* Li-Ion Battery and Micro USB charging port with USB cable (wall adapter not included) Compact Power 40mm length mirrors that of a standard manual screwdriver making use, especially in tight spaces, easy, and storage even easier. Ease and Reliability Simple push button operation with quick change locking collet to hold bits securely. Also includes 3-stage battery charge indication to prevent unexepected interruptions. Work Surface Visbility LED lights activate automatically when in-use