iPod Touch
1st Generation: Rounded metal back. Model A1213
2nd Generation: Rounded metal back. Model A1288
3rd Generation: Rounded metal back. Model A1318
4th Generation: Flat/angled metal back with camera. Model A1367
5th Generation: Flat back in 5 colors. Model A1421
iPod Nano
2nd Generation: Colored aluminum case available in 5 colors. Model A1199
3rd Generation: Fat, square case with a chromed stainless steel back. Model A1236
4th Generation: Tall and skinny curved aluminum and glass case available in nine colors. Model A1285
5th Generation: Aluminum and glass case available in nine colors. Tall, skinny metal. Model A1320
6th Generation: Small square aluminum and glass case design with a clip on the back. Model A1366
iPod Classic
1st Generation: The original iPod with a "Scroll Wheel" in a flat white color. Model M8541
2nd Generation: The "Touch Wheel" with a clear plastic hold switch. Model A1199
3rd Generation: Fat, square case with a chromed stainless steel back. Model A1236
4th Generation: Fat, square case with a chromed stainless steel back. Model A1236
5th Generation: White or black polycarbonite front with a chromed stainless steel back. Model A1136
6th Generation: Silver or black anodized aluminum front with a chromed stainless steel back. Model A1238
7th Generation: Silver or black anodized aluminum front with a chromed stainless steel back. Model A1238