More than one item would be described as items with no apostrophe. Apostrophes are used to show possession, as in "Mike-Ray's grammar is atrocious".
Apostrophes are also used for conjunctions, which is two or more words combined into one, like if you take the words it and is to make it's. For example, "have you seen Mike-Ray's grammar? It's atrocious."
On Topic:. Travel item capacity is grammatically correct, like biosterous said.