Great price for an official microsoft product. Use the £1 voucher attached to get it at this price. Free next day delivery!
"Light Blue rechargeable battery pack for use with the Xbox 360 Wireless Controller.
Convenient, rechargeable power for your Xbox 360 Wireless Controller
Up to 25 hours of play per full battery charge
High-performance NiMH rechargeable battery cell
Battery fuel gauge through the Xbox 360 dashboard
Charger required (sold separately) "