Milwaukee REDLITHIUM batteries are the next generation in Lithium-Ion technology. Compatible with all products in the M12 Cordless tool system. REDLITHIUM battery packs will provide unmatched runtime, performance and durability for the professional tradesman. M12 REDLITHIUM 4.0 provides up to 2X more run-time, 20% more power and 2X more recharges than a standard Lithium-Ion battery. REDLITHIUM 4.0 also delivers best-in-class performance in extreme job-site conditions. with Milwaukee durability built-into each pack, the REDLITHIUM 4.0 battery operates cooler and performs in climates below minus 18°C/0°F with fade free power. The M12 FUEL Cordless Brushless 1/2 in. Stubby Impact Wrench is the industries most compact impact wrench on the market place. Measuring only 4.9 in. in length, this tool fits in tighter spaces, making users more productive.