Two is always better than one, like the pair of counter rotating cutting blades on this handheld circular saw that let it effortlessly slice through wood, plastics and metals in either direction, without any kickback.
The Chicago Electric Double Cut Saw uses a single 7.5 amp electric motor to spin a set of 5 inch cutting blades, in opposite directions, to speeds of up to 4200 RPM. The obvious benefit to having twice the number of blades is also having twice the cutting power, making it easier to hold while sawing through a variety of materials. But the dual system also stops the blades from catching and kicking back, which can be dangerous for the operator.
Source: gizmodo.comAdded: 14 November 2011