Stihl 4002-007-1000 7-3, 27-3, 47-3 PolyCut Blades. This is a multi-purpose cutting tool with three thermoplastic blades that are ideal for hard-to-reach places and large areas of high-growing grass. The blades are mounted on bushings and extend when the engine is brought up to operating speed. The white thermoplastic blades are also ideal for trimming around monuments and other solid objects as they don’t mark the stone. The blades are easy to change and some models can also be fitted with flexible nylon line in addition to or in place of the blades.