Detect alpha, beta, and gamma radiation in mR/hr and cpm. Heavy-duty construction ensures that this monitor will stand the rigors of daily use. Thin, recessed end window permits easy penetration of ions and is protected by a sturdy aluminum grill. The speaker and Geiger-M ler (GM) tube are housed in a rugged case. Replaceable neoprene feet on bottom of monitor let you place unit on bench or desktop ottom face of instrument will not be contaminated. Monitor includes one 9 V battery and a certificate of conformance to factory specifications.