Contractor's Choice Dutch Lap has flat panels that overlap each other with a shiplap joint, with a decorative groove between the laps. This groove improves strength, creates a narrow reveal line that adds visual interest and creates deeper shadow lines. Double 4.5" Dutch Lap has a 4.5" panel exposure. Contractor's Choice offers builders the perfect combination of quality and value. The durable, easy to install panels will hold their own against the elements. And the realistic cedar-look finish will remain attractive for years of virtually maintenance-free use.