The reinforced 14hz geophone for land (ST-14N) is designed equivalent to SM-4 structure, which is for low weight, long field-life,and ultra reliable performance. Precision engineered components and computerized test equipment ensure consistency in manufacture and operation throughout and beyond the limited replacement guarantee period of three years. Precision machine, rotating coil design. Precious metal contacts … Continue reading Reinforced 14Hz Geophone for Land, Desert, Snow, Marsh and TZ