Galvanized steel plate with tan finish. 

Diameter of the opening: 1.5"

Can be placed over the opening of a Bluebird nesting box or a Tree Swallow nesting box, so that squirrels and woodpeckers cannot enlarge the opening.

Dimensions of plate: 2'' x 2''.

Will work for :

Eastern and Western Bluebird

Tree Swallow

Tufted Titmouse

Carolina Wren

White-breasted Nuthatch

Red-breasted Nuthatch

Black-capped Chickadee

House Wren

House Sparrow

Prothonotary Warbler

Will exclude :

European Starling

Great Crested Flycatcher