What are the main differences between MIL-DTL-38999 series I, II and III connectors?

MIL-DTL-38999 series I connectors (Amphenol LJT series) are bayonet coupling connectors, with 100% scoop proof design, available for connector size 9 to 25. Only metal shell versions are available. (see LJT-HE308 catalog)

MIL-DTL-38999 series II connectors (Amphenol JT series) are bayonet coupling low profile connectors, with non scoop proof design, available for connector size 8 to 24. EMI grounding fingers are optional in JT plugs. Only metal shell versions are available. (see JT catalog )

MIL-DTL-38999 series III connectors (Amphenol TV / CTV series) are thread coupling connectors, with 100% scoop proof design, available for connector size 9 to 25. Metal and composite shell versions are available. EN3645 is the corresponding European standard for this series. (see Catalog Amphenol TV-CTV).