DIDA®uses "PCVD" to maximize performance and durability. This latestscientific "State of the Art" technology creates a hard wearresistant, low friction film. Our steel alloy piston ring is coatedwith "PCVD" while our cylinder is coated with a hard durableceramic coating. Together they reduce friction and form a cleanburning system that generates more power, while ensuring longerlife. In addition to these features our "HEMI" head design makesthis saw the most powerful in its class.