[Product Size]Bee Hive Nuc Box Entrance : Diameter: 2.67inch(6.8cm); Hole diameter: 0.94inch(2.4cm); Center hole diameter: 0.16inch(0.4cm). flat head self-tapping mounting screws: 0.16inch(0.4cm) x 0.63inch(1.6cm). Perfect for your hive,Excellent workmanship, for your beekeeping work to provide assurance, beekeeper's good helper [Product Material]Made of high quality stainless steel material, strong, oxidation resistance and resistance, long service life. It is reusable . Performance is far plastic material [Multi-mode Adjustable Design]Fully open, queen exclusion, closed with ventilation and fully closed. Rotatable, so you can easily choose different channels. It's very useful professional beekeeping tool. It can better protects your [Wide Use]These entrance can be used for new nucs five frame boxes, Swarm box, nuc box and split box. Control the entrance of the hive, facilitate the timely of air inside, and effectively keep the temperature and humidity in the hive stable, Manufacturer: CTRLZS