There is some key information brand, model, weight, length and type.
Type – Paintball barrels come in mostly three types. One piece, two piece and three piece. One piece barrels are just a single tube barrel, two piece typical unscrew in the center, three piece barrels also unscrew but the also have a sleeve/insert.
Length – Length in inches
Weight – Weight in grams. Barrels that take an insert and weighed with the insert unless started.