This is a box that looks like a bird house nest box . so very discreet , it can trap invasive English House Sparrows. The trap does not kill . so if you get a good bird in the trap then just let it go . English House sparrows kill other good bird to expand and take over more nesting boxes . if you are not wanting to trap then use the 7/8 oval for Violet Green swallows , see the you tube video (bird house oval entrance hole for Violet Green swallows) or the you tube video (small bird house entrance hole size) email protectswallows. The box for sale can be seen on the You Tube video (English House sparrow Trap box)