Woodlink Copper Top Series chickadee nesting box. This attractive nesting box is constructed from all kiln dried 3/4 inch cedar. The opening is 1.2 inches to permit chickadees or house wrens in but the opening is not large enough to allow house sparrows access. Nest box includes mounting hardware and instructions with a nesting data sheet. 11″H x 7.5″W x 6.75″D / Weight: 3.5 lbs.