Want to make sure you attract a certain bird to your nest box? Besides taking measures like hanging the box in a north-facing position and at the right height, it's also important to consider the size of the house's entrance hole; it plays a huge part in a bird's decision to make a home there or not. We can categorise different birds of a feather, each group with a specific preference for their own little hobbit door size Features and Benefits Protect Your Bird Box Entrance - This protective steel plate provides a strong seal around the entrance to prevent predators, such as woodpeckers, from gaining entrance and harming the nesting birds Choose Which Birds Occupy Your Bird Box - These plates are now available with entrance holes 25mm, 28mm, and 32mm in diameter. You can choose your preferred size from the drop-down menu above Strong Build Quality - Made from stainless steel, these plates are guaranteed years of use Easy Mounting - Simply attach the plate to your bird nesting box usin