72331907
Jul 7, 1969
Oct 27, 1970
ELECTRONIC HAND-HELD METAL-MINERAL LOCATOR, OPERATING ON A BEAT-FREQUENCY PRINCIPLE, AND INDICATING THE PROXIMITY OF METAL AND/OR MINERALS BY SOUND AND BY INSTRUMENT DISPLAY, NORMALLY USED TO DETECT METALLIC OBJECTS OR MINERALS UNDERGROUND OR IN WATER
Housewares and Glass