One Item with 3 different dimensions to be created

We are trying to create below items

ClientX Box

• Small Box: A" x B" x C"
• Medium Box: X" x Y" x Z"
• Large Box: P" x Q" x R"

We know we have option to create 3 different items based on dimensions.

Any way we model this item as a Box and 3 items with Small, Medium and Large related to the Item Box. (like a hierarchy or relationship).

Please let us know for any pointers