The filename follows Cisco's standard naming convention, which tells us exactly what is "under the hood":

Because it is a virtual image, you cannot change the SDM (Switch Database Manager) template as you would on a physical switch to allocate resources for IPv4 or IPv6 routing. It generally defaults to a balanced template.

i86bi indicates it is built for 32-bit Intel x86 Linux systems. Use Cases in Labs

After adding the image to your IOU device template: