Cantex supplies all information to Home Depot. Home Depot determines what information to include on their website.
The size is displayed on the selling container. I have used this product in all my outdoor wiring, deck, outdoor kitchen, and to connect my shop, underground to my home. Excelent product..
These items are displayed in boxes or containers with the size clearly marked on front panel. I have purchased several different sizes over the past few years and have had no trouble finding the correct product I am looking to buy. These items are well built and will outlast whatever project you use them for.
This box come in 1/4, 1/2, 3/4, and 1 inch so no reason to cut out opening.
No only metal electrical boxes should be used with metal rigid ducts.