Sensitive geiger counter kit uses a Russian geiger mueller tube and is sensitive to Beta and Gamma rays. Want to know if that orange colored plate that was all the rage in the 60's is radioactive, how about your dad's radium dial watch, or the mantles on your camping lantern -this will tell you! Produces the familiar audio clicks and lights up a blue/green LED in response to radioactive sources. Random clicks are even heard from your kit as cosmic rays strike the tube! Uses a Russian GM tube that was made during the cold war (we test every one for proper operation), various resistors, capacitors, and a special miniature speaker. Operates from one 9V battery (not included). Comes with all parts, PC board, GM Tube and instructions (no case available). Size of PC board 4-5/16" x 1-1/2". Skill Level 2. Requires soldering.