Our 10 frame flat migratory lids are made with HDO plywood to last. Dimensions are 16.25"x21.75" with .75" cleats on each end, leaving around .375" of extra room in case your boxes have swollen. 71mm holes can be drilled for feeding at customer's request.
What is HDO Plywood? High density overlay plywood is made with much more resin than standard plywood and is bonded under heat and pressure, helping to keep it dimensionally stable and resist warping. The high density overlay outer layers repel water which means when you properly prime and paint the edges of the plywood you will have a product that lasts 2-3x as long as equipment made from pine. Stop replacing your equipment every few years and buy equipment that lasts!