MIL-DTL-38999 Series III Circular Connectors TE Connectivity's (TE) DEUTCH MIL-DTL-38999 Series III Standard Circular Connectors are designed for use in harsh military and aerospace environments. TE's Series III connectors offer high-density layouts with up to 187 data connections and power contacts rated up to 23A. These connectors feature triple-start couplings with anti-decoupling ratchets for high vibration applications, grounded plugs for superior EMI shielding, and 100% scoop-proof contacts for blind-mate coupling.