The MX12CB is a chassis-mount contactor designed for high-current switching applications in demanding environments. It features a 200A continuous current rating with maximum short-duration ratings of 1200A at 10 seconds and 300A at 90 seconds, utilizing silver contacts in a single-pole, normally-open (SPST/NO) configuration. The device incorporates a hermetic EPIC® seal with ceramic-to-metal braze and gas-filled chamber that exceeds IP69K protection standards, enabling operation in extreme conditions including waterjet spray (2750 psi), steam (105 psi), and salt-spray corrosion environments per MIL-STD-810G. Operating temperature range extends from -55°C to +100°C with testing validated to 200°C, and the contactor withstands high shock (10–200 Hz, 20G) and vibration (sawtooth 20G at 1 ms, sine 25G at 11 ms) for rugged off-road and tracked vehicle applications. The case is constructed from 25% glass-filled nylon 6/6 (UL 94 V-O), with power terminals using stainless M10 × 1.5 bolts and silicone-insulated 20 AWG coil wire (UL VW-1). Available coil options span 12VDC to 240VDC with optional dual-coil designs featuring no PWM or EMI emissions and built-in coil suppression, making the MX12CB ideal for battery management systems, electric vehicle power distribution, renewable energy systems, and industrial switching applications requiring reliability in extreme conditions.