... resist cracking, and stay flexible. Residential grade. Nylon trimmer line(grass trimmmer line)Feature:1,Suitable for most ... weld-resistant performance4,Directional aerodynamics always presents the cutting blade forward5, Premium copolymer formulation for commercial toughness 6 ... :round, trigon, square,star,hexagon,heptagon,twist,saw blade,trigon,etcPacking:card head,loops/donut,blister card ,blister ...