Panels in old pine wood, white and red fir (types of mixed wood) looking vibrant and strong. Sound knots, dead knots and knots whisker are allowed, allowed resin pockets, irregular natural woodworm holes, cracks, sapwood, nail holes. Are allowed small pieces of other material (nails, ..), bevel and mechanical damage. The different colors (brown, gray, dark gray) are a specific characteristic of this material. Bonding of the slats on the soul. The long sides of the slats are not glued. Retro: Spruce C, without any special requirements, retro unpolished, not plastered or repaired. Note: This panel meets the requirements defined by ÖNORM M6219-1: 2010 for use in the sauna.