The Mossberg FLEX Conversion Kit Stock Adapter will allow you to convert your existing Mossberg 500, 590, 590A1, 535, 835, or Maverick 88 shotgun and gain the convenience of quick-change FLEX TLS-enabled components. Includes the stock adapter only. Requires a FLEX stock (sold separately). Note: Not compatible with 590 Shockwave or Compact Cruiser