Add a 3.5 inch PVC porch to any Natural Gourd, S&K Mfg gourd, or custom house
"Customer must drill holes to mount on there particular configuration"
They are perfect for the natural gourd. Just use some Lexel glue to attach it to the gourd.
Also can add a Porch to Houses, Plate Entrances, Gourds or any home made product to produce a porch view to see the Purple Martins.