I bought a 21 oz from another vender and returned it. With ice all the way to the fill line I could barely get 1 can of pop in there.
With the 27 oz, same scenario, I can get 1.5 cans of pop in there, and it's not all that heavy. REALLY keeps things co.`ld and ice stays solid for at least 24 hours
This review was written in the old system and had content requirements that are different than reviews written today.