Bosch Bare-Tool DDS181B 18-Volt Lithium-Ion 1/2-Inch Compact Tough Drill/Driver (Discontinued by Manufacturer) 4-Pole open frame motor - more power in a smaller size New ergonomic design - for outstanding comfort Dura shield housing - constructed to withstand jobsite conditions Ratcheting single sleeve 1/2-inch chuck for one handed bit changes Flexible power system - compatible with all Bosch 18-Volt Lithium-Ion batteries 4-Pole High Performance Motor - For maximum power in the most compact size New Patented Gear Train and Clutch - Enables most compact design in its class and lightest weight Flexible Power System - Both DD and HDD are compatible with every 18V Li-ion Bosch battery Ergonomic Grip Zone - Smallest diameter in market enables better gripping and greater comfort New Ergonomic Design - Modified orientation relative to handle increase comfort