The Valkyrie Inner Canvas Cover is included with each Valkyrie order and is placed directly on top of all 24 frames. The colony propolizes this cover and it helps seal in the heat and humidity levels. Used together with the Triple-layer Wool Blanket, the Inner Cover is part of the Valkyrie System: "Easier for the Bees, Easier on the Beekeeper!" For whatever reason, when an additional cover is needed, order it here.