This is a connective piece for the apple bluetooth keyboard and trackpad. I somehow ended up with an extra one when someone saw it on my amazon wishlist and bought it for me after I had already ordered it for myself, and so I have this one to get rid of – it's in new condition, and is still in its packaging.
It's pretty useful for having a keyboard/trackpad combo for an entertainment setup (I tried one of logitech's keyboard/trackpad combos, but I hated the surface of the trackpad).
Retail on it is $30, and the new and used section doesn't have them for less than $23 (with the shipping).
I'm willing to sell it for $15 which I think is a more reasonable price. Pickup can be made around campus, mountain view or los altos.