R. STAHL Series 8579/31 sockets for Zone 1/21 in a 4 and 5-pole version have full AC-3 switching capacity up to 63 Amp. The high degree of protection IP66 guarantees the highest level of protection against the penetration of dust and water in any application position. Self-cleaning lamellar contacts provide optimum contact and the plugs can be inserted and removed in the zero position quickly and easily. The load disconnect switch, with mechanical locking device and a handle that can be locked in the 0 or I position, is an additional safety feature.