Profile: Sankosha manufactures ceramic gas tube surge arresters, gas discharge tubes and circuit protection devices. We supply san-earth, the original earth ground conductive cement used to produce permanent and maintenance free grounding systems for lightning and power surge protection. Our surge protection devices have well defined surge-limiting characteristics enabling them to spark over (or breakdown) when the abnormal voltage on a line reaches a specific level. Our gas tube arresters protect the equipment and circuitry from abnormally high voltages caused by lightning or electrical transients.