Hey! So, the FLEX STACK PACK 3-Piece Storage System has three boxes, each with their own specific dimensions. I got the details from the manufacturer's product description, so here’s the breakdown for you:

• Rolling Tool Box: This one’s the biggest. It measures 22.8 inches tall, 15 inches wide, and 20 inches deep.

• Medium Tool Box: More for medium items. It's 13.6 inches tall, 15 inches wide, and 20 inches deep.

• Small Tool Box: Great for smaller stuff. Dimensions are 6.7 inches tall, 15 inches wide, and 20 inches deep.

Each box interlocks with the others using an auto-connect system, which makes stacking them up really easy and secure.

From our research, it’s clear that people love the gas strut lids in the medium and rolling boxes because they hold the lids open, which is super handy when you're busy with both hands.

As for durability, this system has IP65-rated all-weather protection, meaning it can handle pretty rough conditions.

It’s also got an impact-resistant body with aluminum corners, so your tools should stay safe. The whole setup can carry up to 500 pounds, so it's definitely built to handle some heavy-duty work.

Hope this helps!