The SuperGourd Tree Swallow has a 1 & 1/2-inch round entrance that
is ideal for tree swallows, bluebirds, and wrens. The seamless, 10-inch, one-piece gourd
has a heavy duty cap for easy
access. The gourds have UV-inhibitors for long life. Seven 5/16-inch
holes in the bottom help with drainage. Compatible with the SuperGourd Insert Trap SGIT-TS.