Assemble this high-quality ultrasonic detector and hear sounds normally beyond human ears! Listen to the sound of bats as well as other things that emit ultrasound. You’ll be surprised to discover the number of usually inaudible sounds that surround us every day! * Assemble your own working ultrasonic detector * Give your ears superpowers and listen to amazing new sounds! * Clear, step-by-step instruction booklet * Easy-build kit – simple push-fit connectors and screw-together parts * Requires 1 x 9V battery (not included)