A friend gave me his old GoPro Hero 2 so I was looking for some accessories and came across this last night. Seems like a great selection of bits and has excellent reviews so for this price you can't go wrong! Says it's compatible with all versions of GoPro Hero too.
Price shows at £15.99 but just underneath there's an orange Promotion Message button that gives 7 quid off (there are other offers too but the £7 one seems the best unless you're buying a truckload lol)
Edit: You can also enter code B9YGTQZX at checkout (my mate wasn't seeing the Promotion Message thing so they sent him the code this morning)