The 221 series Lever-Nuts Ex is suitable for extreme and hazardous applications. These splicing connectors obtain AEx (Class 1, Zone 1) rating when used in conjunction with the mounting carrier, whether clamped onto a DIN rail or fastened to a smooth surface. The series is UL-listed for use with solid, stranded, flexible and tin-bonded wire with a range of 24-12 AWG. When connectors are flush together within the carrier, the working voltage is 275 V. For applications working with voltages up to 440 V, the connectors are inserted so there is a visible space between each connector.