KOHLER K-5529-NA Invigoration Series Steam Generator, 9 kW Fast-response technology produces a luxurious steam shower in 60 seconds Power clean technology offers one-touch automatic cleaning and safe maintenance 240 cubic feet maximum volume rating for custom showering applications Compatible with the KOHLER dtv+ showering system Requires k-5557 invigoration steam generator control kit or k-5548-k1 dtv+ steam Adapter kit (sold separately)