Millennium Treestiand B1 Ladder Stand Cover Blind The B1 Series Blind is a perfect match for any of the L-Series Ladder Stands (excludes L360). The B1 is made from heavy-duty, weather and mildew resistant material that will protect you from the elements and is quiet to the touch. The B1 also features a front zippered entry and multiple window configurations so hunters can customize their viewing and concealment options. Features: Perfect match for L-Series Ladder Stands except L360 Heavy duty Weather and mildew resistant material Protects you from the elements Quiet to the touch Front zippered entry