You put the depotted eyeshadow into a pro palette by applying a magnet on the back of it, then place in either a 4-pan or a 15-palette, which you can buy at MAC stores. You cannot buy the single e/s pans empty.
As there have been many threads on depotting and depotted e/s from MAC, I am locking the topic. Please utilize the Search function on this board to find more threads on depotted e/s.