Our BestBasic Medium Bat House features a single chamber and holds up to 30 bats. * The interior surface and landing platform are screened to make it easy for bats to cling when roosting and landing. * Constructed of white pine and weathers beautifully. Mount to a tree, building, or pole. * Houses 30 bats to help control pesky insects around the house. * 12 x 17-1/2 x 3 inches.