Bat calls are heard clearly through an internal speaker - no clumsy earphones or earpieces to play with. * 1/8 inch standard female audio output jack allows the recording of bat calls on a tape recorder or Personal Computer, etc. * Complete conversion of ALL bat echolocation frequencies. No tuning required. No missed bat calls because you are "tuning the dial." * Dimensions: 4.25" x 2.75" x 1" * Uses one 9 volt battery (not included)