The outer shell has been precision cut and uses an ingenious system of tabs to hold it together. This further extends the lifespan ensuring that there are no fixings holding the weatherproof shell together that could rust or degrade over time. Internally there is a removable wooden nesting chamber with drainage holes for the birds to nest in. This is constructed from Oriented Strand Board, which is made from flakes obtained from wood waste or from saplings thinned from forests to make space for larger trees. If you need to check or clean the box it is simply a case of twisting the fastening at the bottom and the wooden nesting chamber slides out.Fixing to the wall or tree is easy with three concealed mounting holes in the back of the box (located opposite the entrance hole for easy access). Often this is the only fixing needed, but a further hole is provided at the base for use when necessary. The easiest way to mount the box is to remove the inner, fix the outer shell onto the tree, wall etc. then slide the inner roost chamber back into the box and secure it in place.Features:Designed with a 45mm entrance hole especially for starlings.Unique innovative construction; recycled plastic outer shell with wooden internal nesting chamber.Provides a robust, long lasting and comfortable home for starlings.Ideally place a few of these boxes on adjacent trees or buildings to encourage a loose colony to form.Specifications:Material: Recycled LDPE plastic outer with internal OSB nesting chamberConstruction: Outer recycled plastic panels fitted together using integral tabbing system. Internal nesting chamber stapled togetherFixing: 3 concealed keyholes and further fixing hole at base for added stability if needed.Dimensions and WeightDimensions: Height 35cm, Width 20cm, Depth 18cm1.7kg