1. Made of high-quality stainless steel, it is not easy to deform and rust. 2. Installed on the beehive, used to adjust the size of the beehive entrance for bees to enter or isolate. 3. There are four ways to open and close: fully open, queen elimination, closed ventilation, and fully closed. 4. It is a great tool for beekeepers. 5. One package contains 30pcs.