Refer: Electronics Australia May 1998 This kit assists people who have difficulty in hearing high audio frequencies, or for those who want to hear more than their normal unaided ear. By amplifying these high audio frequencies, not only will conversations be made clearer, you will be able to hear noises not normally heard such as insects or a watch ticking, for example. Built into a small case and powered from a 9V battery makes this kit totally portable. Use it as a hearing aid or for a fun & educational purpose. Kit supplied with Case, Front label, PCB, 9V battery, and all electronic components. Headphones required. Note: Not a replacement for a proper hearing aid.