Used probably for 8-10 days tops. They were my son's boots for 1 season (before having a place at the loaf). The liners don't even look used. Size US 8/UK7 / Boot Sole length is 305. The mondo size isn't listed on the box or the boots, but if I had to guess, I would say 25.5-26.5 based on BSL.
These look like they just came out of a store with box, tools, and manual. Only way you would think they were not new is by the soles which show that they have been walked outside in. Can send pictures for interested buyers.