1. Diecasted of Al-alloy shell with and plastic-sprayed surface; 2. Socket has open-close indicator; 3. Branch pole number and current mixed divice is convenient to maintain current; 4. Can be matched with general switch for protecting the circuit from the damages of overload and short; 5. Can be customized according to users requirements. 6. Suitabe for GB3836-2000、IEC60079、GB12476.1-2000、IEC61241 standard request.