: Refers to the internal hardware generation, specifically for the Aironet 1700, 2700, and 3700 series.
There are two common ways to make this firmware "work" on your access point: Ap3g2-k9w7-tar.153-3.jbb1.tar WORK
AP 3702i - IOS version for Autonomous Mode - Cisco Community : Refers to the internal hardware generation, specifically