Ikea kallax brackets

I needed some cheap shelves for my Ikea Kallax unit however I wanted something robust and quick to do. So I created this brackets. Using carpet tape to stick them onto the sides and then cut some 12mm plywood shelves. It also means that these can be removed without damaging the unit. You need a pair at the front and also at the back. The ends stop the shelves from slipping. Let me know if you have any comments