Our most economical walk-in shelter, the “Rook” is 7’3” inside diameter at the base and is 7’ high. A 31” x 64” walk-in door, lift lug, inner tie downs (for anchoring shelter to wellhead), anchor holes in the base flange and R-10 urethane insulation all come as standard features. Walls are slightly tapered from bottom to top to allow nesting one inside the other for transporting. Options include louvered vents plexi-glass windows, gas detector inspection doors and custom coloring. Explosion proof CATA-Dyne heaters may also be included with your purchase. As with all products manufactured by D & G, only high quality virgin polyethylene is used.