It is 2.75" - You can fit up to 9-pellets of #1 buck in a 2.75" 20-gauge shell. This is 10-pellets of #2 buck. The 3" version is 18-pellets of #2 buck.
I presume Federal tried some #1 buck variants and either could not get them functioning the way they wanted accuracy or penetration wise. I know I would prefer 8 pellets of #1 @1200fps to 10-pellets of #2 at 1325 - but I'll take this over what I currently have - nothing.