The LND-712 is a very popular domestic tube currently made by LND, Inc. in New York. LND is one of the few remaining domestic (American) producers of high quality Geiger tubes. This model is known for its high sensitivity to Alpha particles, in addition to detecting Beta, Gamma, and X-Ray radiation. It is used in a large range of domestic and foreign Geiger counters. https://www.youtube.com/watch?v=JCI4IuTP0RU https://www.youtube.com/watch?v=N2IVUtmoO9s https://www.youtube.com/watch?v=oiOWGzxnyCI https://www.youtube.com/watch?v=4zTFFzAyxU4