Customer Testimonials:
"Two years ago I was having many problems with hammer switches from other manufacturers, which sometimes lasted no more than 10 blows before they broke down. These switches were twice as expensive as GISCO's. I sent an e-mail to GISCO and asked for their hammer switches, as I desperately needed an alternative... (they) provided me with the best hammer switch I ever used. We have 3 more of these switches now, but the first unit we bought has been constantly working for 2 years and has not missed a single blow yet!! I recommend these switches to anybody that does seismic work. They are extremely reliable." -Jose R. Arce, Manager Jose Arce Geofisicos S.R.L. Lima, Peru