Provides you with full protection: Each tool is individually tested at 10,000 V AC and approved for 1,000 V AC. Safe installation of terminals and connectors, conductor connections, and fastening of busbars. For work on live parts up to 1,000 V AC. When working on live parts, the safety of the user is the top priority. Wiha's insulated socket inserts are the ideal tool for working on electrical installations. In combination with the insulated ratchet wrench or cross handle adapter, the socket inserts can be used for tightening and loosening hex screws. The insulated socket inserts are subjected to individual testing in accordance with the international standard IEC 60900, allowing for safe work on live parts up to 1,000 V AC. Only compatible with Wiha's insulated ratchet wrench and cross handle adapter.