Compatible with Worx String Trimmer Models: WG150, WG151, WG151.5, WG152, WG153, WG154, WG155, WG155.5, WG156, WG157, WG160, WG160.1, WG160.2, WG163, WG165, WG175, WG180. Tool-free spool cap. It protects the line and holds the spool in place.