Well, this is 2021 and my original iPhone 4 battery just quit. I use the phone as a data backup - not calling. The Ifixit kit was awesome. Phone repair places will not touch an iPhone 4 anymore. I read the instructions and the comments. My battery replacement well perfect. I can see that ifixit listens to comments, because the new tool set addresses some of the earlier comments. Thanks a lot. I’ll recommend you and use you in the future. Good Job !!