As mentioned elsewhere, 2S (two-cell) LiPo packs must be balance charged. The adapter allows either a 1S or a 2S battery pack wired with only a JST-XH connector (3-pin) to be charged using the iMAX B6 or B6AC charger.
The charger comes with several adapters to connect the discharge connector on many packs. One of the adapters included has an odd-looking 1/8″ phone plug on it. I’ve never run across anything with that kind of connection, so I cut the 1/8″ plug off and used the remaining connector to make this charge adapter.
Typically, 1S packs use a 2-pin JST-XH connector. If you have a mixture of 1S and 2S packs, I suggest using a 3-pin connector on all your battery packs. That way, only one charging adapter is required, no matter what you’re charging. Just be sure to only charge your own LiPo packs with your adapter cable, and only charge your LiPo packs with your own adapter cable!
If you’re going to be using 11.1v 3S packs, wire everything using 4-pin JST-XH connectors instead of 3-pin.