These 6-5/8" unassembled medium hive boxes are made of Ponderosa pine, and jointed here in the Northwest. The boxes are often used for honey supers but are also use by some beekeepers as brood chambers. Like all pines, it is important to paint the box with an exterior latex or treat it with on oil annually. Tung oil is a good choice. These may contain small knots (if any) or superficial blemishes, but are very structurally sound.