Walnut plank in 3-layer construction with small bevel on long side and approx. 4 mm top layer, with approx. 4 mm backing in the same wood and middle layer conifer. Tongue and groove on all sides for easy installation. Sapwood possible, healthy knots, also repairs up to max. 15 mm diameter and spot fillings are permitted. Small open cracks and unsealed spots of a few millimetres are permitted.