We call this the hardwood helper. It's designed to reduce mill glaze, the gray and prepare the wood for finishing.
Pro-Tech Brightener (Step #3)
Annihilates tough tannin stains and watermarks on all types of wood, decking, siding and fences; removes mill glaze. Penofin Pro-Tech Brightener re-establishes the Ph balance of your wood after stripping and cleaning and brightens gray weathered wood to bring back that mill-bright color.