Discover the secret world of bats with Checker Tobi using your own bat detector. With this exciting kit, you can hear the ultrasonic calls of bats and find out which bats are flying near you. Thanks to the simple and helpful instructions, the detector can be quickly assembled, and you can immediately start your exploration. Assemble, turn on, and start discovering. Box contents: detector board, ultrasonic sensor, speaker, housing, instructions (A3 poster, double-sided printed). Additional requirements: 9V block battery, rubber band. Age: 8+.