I have a 4th generation iPod color 20GB. I tried to replace the hard drive with KingSpec 32GB SSD it didn't work it had formatting issues. I then did what most people do and bought a compact flash (CF) to 50 pin 1.8” IDE adapter. The adapter I bought came with a case the adapter's circuit board is red and has a master/slave switch on it. The case looks like a hard drive so the padding and bumpers on the Ipod's original hard drive can be reused with ease. Some people have had success with the KingSpec's SSD it is a nice option because it doesn't need an adapter. I have seen talk on the internet about iPod logic board versions and drive compatibility so maybe this is why the SSD didn't work for me. The key to converting to solid state is having a good adapter with the right brand and model of CF. I used a Kingston Ultimate 32GB CF it was indicated on Tarkan's website to be compatible with all iPods. Everything works perfectly now after installing the CF card with adapter.