This Assembled 6-5/8" medium super is finger jointed and made of Ponderosa pine. These boxes are assembled at our own local wood shop. The boxes are glued and stapled with electro-galvanized staples at each finger. Stapled joints naturally counter sink, which allows you to fill them to provide extra protection from rust, and achieve a very smooth finish. We do not fill the staple holes. Like all pines, it is important to paint the box with an exterior latex or treat it with oil annually. Tung oil is a good choice. The box may contain small knots (if any), or some superficial blemishes, but is very structurally sound.