The Milwaukee 2719-20 M18 FUEL HACKZALL is the fastest cutting and most powerful one-handed reciprocating saw. Utilizing a POWERSTATE Brushless Motor and a best in class 7/8" stroke length, the M18 FUEL HACKZALL cuts up to 50% faster than competitors. Our M18 REDLITHIUM XC5.0 Battery delivers up to 2.5X more runtime, 20% more power and 2X more recharges than standard lithium-ion batteries. The lithium-ion battery pack features superior pack construction, electronics, and performance giving you more work per charge and more work over pack life than any battery on the market. The rechargeable battery also offers you 5.0 amp-hours of runtime. Each battery pack is durably built for heavy-duty use, runs cooler, and performs in climates below 0°F/-18°C.