Don't know without closer inspection but based upon the photograph, I do not discount the possibility that it is proseal. Masked off and lightly smoothed (often using a proseal filleting spoon), an "A" mix of sealant can easily render the same dark, shiny look. My yeoman's effort to pleasingly fill in a gap with B4 sealant is no match for that builders eye towards cosmetics...whatever medium he chose.Does anyone know what the product is used to seal the canopy to the fiberglass in this photo?