Oak 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. For the main part the planks have healthy knots. Stress cracks up to 30 cm, also torn knots and small knots are sealed with appropriate wood putty. Repairs up 25 mm diameter are possible. Small open cracks and unsealed spots of a few millimetres are permitted. Very robust floor planks, suitable for commercial use.