I bought a Bluebees ventilated bottom board for SHB and Varroa, but it is not a complete bottom board just a plastic insert to fit into a modified base that I have to find from somewhere else. Although J-Pierre Mercader, the inventor, states that you can modify your existing bottom board to fit the vented insert, in practice this is not possible for two reasons. Firstly the vented bottom board will not fit a standard size base. Secondly, the amount of work required to fit the vented bottom would require the complete destruction of the existing base making the base unusable. Other people I know who have purchased a Bluebees vented base were sold by the advertising, but when it arrived they quickly put it into a corner to collect dust. I have asked J-Pierre how to overcome the problem that I still need to buy a suitable base that will take it, but I only get the reply that it is easy, which it is not. Notice that none of his ads show detailed photographs of the vented base. If you plan to buy a vented base look elsewhere as there are plenty of products available that provide a complete solution.