Article: iPod Nanos have been released in five major different forms. This can give you a quick idea of how old yours is. Rectangular with touch screen 7th Generation (2012 - 2015) Square with touch screen 6th Generation (2010) Rectangular with click wheel 4th and 5th Generation (2008 - 2009) Wide screen with click wheel 3rd Generation (2007) Small screen and click wheel 1st and 2nd Generation (2005 - 2006) You can find the iPod Nano's model number on the back of the iPod itself, near the bottom. The following model numbers correspond to the following generations: A1446 7th Generation A1366 6th Generation A1320 5th Generation A1285 4th Generation A1236 (The serial number also ends with YOP, YOR, YXR, YXT, YXV, or YXX) 3rd Generation A1199 2nd Generation A1137 1st Generation

What is a summary?
Look at the form factor. Check the model number. Compare the model number to a generation.