The MIL-DTL-38999 Series II connectors are designed for harsh environments, featuring up to 128 contacts in an insert. With environmental sealing and an operating temperature range of -65 °C to 200 °C, they ensure reliable performance in demanding conditions. Available in various mounting options such as front and rear wall mount, jam nut, and box mount receptacles, these connectors offer versatility in installation. Constructed with aluminum shells and offering multiple plating options including cadmium-free finishes, they meet stringent military specifications. Utilizing M39029 rear release crimp contacts, they provide secure connections with options for straight, RFI grounding, and standard plugs. With 52 insert arrangements and sizes ranging from 22D to 12, these connectors cater to diverse application needs. The gold-plated contacts ensure optimal conductivity, while the bayonet coupling mechanism allows for easy and secure mating. Suitable for environment-resistant box and through bulkhead mounting, these connectors are designed for service class E applications, with a mating life of 500 cycles.