Coveside Sunshine's Bat Hse - Large Echolocation slots on sides help bats to find inside cavity Screening gives bats surface to cling to Handcrafted of 1" eastern white pine for insulation because bats like temperatures of 100 to 100 degrees F Partitioned into two chambers inside with landing pand and opening at bottom for bats to enter This size holds 100 bats - comes with an instruction packet