Compatible with Multiple WROX String Trimmer Models - WG150, WG151, WG151.5, WG152, WG153, WG154, WG155, WG155.5, WG156, WG157, WG160, WG160.1, WG160.2, WG163, WG165, WG175, WG180. 110 LBS Tolerable Weight - 0.065in. diameter/10ft. length trimmer spool provides 110 lbs. tensile strength. Our premium weed eater string is stronger than the competition. Plus, its pliable and flexible design allows it to stretch and cushion on impact, making for more efficient cuts. Aerodynamic Shape - The unique shape of the trimmer spools reduces drag, allowing for more efficient cuts and a smoother trimming experience. Like sharp scissors, the weed is cut with ease. This will be your right-hand man to clean up your lawn. Made of High Quality Materials - PA6 (Nylon) + 10% GF (Glass Fiber). Adding just the right proportion of glass fiber to the nylon material not only dramatically increases the stiffness of the spools and caps, but also enhances wear and heat resistance, effectively extending their life. This is a feature not found in other ABS plastic spools and caps. Included: 8pcs replacement Trimmer Spools and 2pcs Spool Caps.