The spool fits multiple trimmer models: WG150, WG151, WG151.5, WG152, WG153, WG154, WG155, WG155.5, WG156, WG157, WG160, WG160.1, WG160.2, WG163, WG165, WG175, WG180, WG163E.9, WG163E.6, WG163E.3, WG163E.2, WG163E.1, WG163E. Abrasion Resistant: The trimmer spool is made with an upgraded polyamide nylon material that has a tensile strength of over 100 lbs and is 30% more durable than other brands for a longer life long. Efficient Cutting: 16 Spool Trimmer Line, 4 Spool Cover, 30ft 0.065" Trimmer Line Spool adopts an aerodynamic elliptical shape reduces drag, bendable and flexible, allowing the line to stretch and cushion the impact with hard surfaces, and increases cutting efficiency by 50%, making each spool cut more weeds. Easy to Use: The trimmer spool automatically feeds the trimmer by centrifugal force, reducing the trouble of manually sorting the spare spool during work.