Bird Abode Supergourds BASGPORCH Plastic Screw on Porches for Crescent

These optional. ribbed plastic porches bolt securely on both the inside and outside of crescent-holed SuperGourds allowing martins easier entry through the snug. starling-resistant entries. Porch is 2-7/8 inch long by 3-1/2 inch wide. It is recommended that these porches be secured flush with the bottom of the crescent hole using threaded 10-32 x 3/4 inch bolts and nuts (included). and that you fill any gaps with 100% silicone caulking. Porches come pre-drilled. with two nuts and bolts per porch pair. and include attachment instructions.Depth: 0.25Width: 3.50Length: 2.88