Single hooks and double brackets for Whalen industrial rack

Link to the Whalen industrial rack from Costco, item 956886.

The top of the double bracket needs to be carefully positioned with the Whalen's holes then slide it down until you feel it's hooked in. Gently tap the bottom feet into the bottom holes. It's a great snug fit. 

The attachable piece needs to keep its dimensions so it will fit properly with the dimensions of the bracket's hook.

Add-on designs I made from the double bracket and attachment piece (warning - they will not work with the two left and right single hooks):

Tray for Whalen industrial rack 

Tissue box holder for Whalen industrial rack