BOLT

Seismic exploration machines and apparatus, namely, seismic air guns used in seismic data acquisition and seismic studies and parts therefor, solenoid valves, time break solenoid valves, and electronic firing controls for firing seismic air guns, namely, electronic circuits and electronic circuit boards, switches, openers and closers all for controlling discharge of seismic air guns used in seismic data acquisition and seismic studies