Geophone: There are three kinds of geophones which are HKJB series intelligent earthquake geophone, HKXJ serial high false frequency geophone, HK20DX serial high false frequency geophone and HK-10 Super Seismic Geophone. They have lots of characteristics, such as intelligently adjust efficiency element of the detector set; strong power of anti-interference; good coincidence; controllable magnitude-frequency characteristics; little phase distortion and to enhance the efficiency of earthquake explore outdoors. Especially our HK-10 Super Seismic Geophone, its distortion is less than or equal to 0.1%.