Gasproof. Approved acc. to ISO 8846. Breaking capacity 250 A/24 V. Short-time current 1000 A DC/5s. Thermoelectric current 250 A DC. Isolation voltage 1000 V DC. Housing flame-proof Polymid Contact bridge and pole screws - DIN 1787 CU = 99.99% - Tinplated. Lock nuts: Stainless steel.