Works good in my GameBoy Advance SP. I took my original GBA Battery apart so I could use tho contacts from it. Soldered the new battery to the contact thing and now I have a bigger new battery in my GameBoy! Arrived in time, but did take over a month. But that was not important to me.
Received. Label on battery says 1000 mAh, actual measured capacity is 960 mAh. Still better than advertised )