This SB50 (Anderson) to 8mm barrel connection is an adapter that plugs into the SB50 of the Bugout 130 extension and can charge battery boxes with built in solar controllers through the 8mm input. The center pin is smaller/thinner than the DC8020 (0.9mm). Jackery, Goal Zero Yeti, and others commonly use this input for certain models like the Explorer 240, Explorer 290, Explorer 300, Explorer 500, Explorer 550, Explorer 1000. 

For Explorer 600 Plus, 1000 v2, 1000 Pro, and 1000 Plus use the 8mm DC8020 with the thicker center positive pin.