Runners, cyclists and other outdoor fitness enthusiasts are probably familiar with ANT+, a data-streaming technology that allows sensors like heart-rate monitors and bike speed or cadence sensors to communicate with something capable of displaying the data, like a watch — or a phone.

Problem is, only a very few handsets, like the Sony Xperia Ion, come standard with ANT+ technology built in. That’s where the Selfloops adapter comes in handy, allowing all those fitness sensors to talk to your phone — and it doubles as a massive 2000 mAh battery as well.

Selfloops says that, while other ANT+ adapters are out there, theirs is the only one that’s compatible all the way down to late Gingerbread — 2.3.4, to be exact.

Nice to have options, though the massive form-factor might create issues (like, how the hell are you supposed to mount this thing on a handlebar?)

The Selfloops adapter arrives in October at $115.