Poly-Dac also know as Poly-Plus, Extralene and Superflex. Each of the three strands of polypropylene is wrapped in polyester aka Dacron to give it great feel, knot holding and abrasion resistance. It is more expensive than poly-pro but less than nylon. It has a specific gravity of greater than 1.0 and therefore is a sinking line up to 1-½” diameter. It is used extensively in the utility industry, window cleaning and by tree arborist where resistance to abrasion and handling is very important. Usually we have it in a Danline or Superflex version made with higher strength poly pro increasing its tensile shown above by 20%-35% depending on the size for the same price