Very proud of my seniors, they worked on a time-lapse video for the shop to demonstrate a project in exploratory. This kit in an inconspicuous place with light shining on it and it remains perfectly silent, however, as soon as the light is turned off the kit emits a high pitched irritating tone! When they turn the light on again to look for the culprit it keeps silent again! Easy to build and loads of fun to use.
A fully detailed instructions on how to build this kit is on the link below