The new, robust 2621 mechanism design is inspired from the M18 FUEL™ SAWZALL®. The upgraded gearing and mechanical components provide added durability. New bushing and seal prevent water and debris from entering the gear housing. Added flange prevents water from entering the motor housing. Improved, advanced overload and thermal protection extends the life of the tool. Gear protecting clutch protects the tool when the blade gets pinched or jammed.