MIL-DTL-38999 III (D38999) harsh environment connectors, designated as SKU D38999/20FC35PA, are essential components for rugged electronic applications. Featuring wall mount receptacles, jam nut receptacles, and straight self-locking RFI plugs, these connectors offer versatile connectivity options. With 9 shell sizes and 54 insert arrangements available, they accommodate various contact configurations, including M39029 contacts in sizes 22D, 20, 16, 12, 10 power, and 8 twinax. Constructed from durable materials such as aluminum, stainless steel, and lightweight composite, and boasting a range of plating options from olive drab cadmium to passivated stainless steel, these connectors ensure reliable performance in diverse operating conditions. The MIL-DTL-38999/20 connectors, with a shell size of 13 and contact layout C35, specifically feature a wall-mounting flange receptacle design with removable crimp contacts for efficient installation and maintenance. Rated for use in harsh environments with a service class of F and a service rating of M, these connectors guarantee high reliability even in demanding military and aerospace applications.