a sizzix adapter is a square black piece of hard plastic which fits over a quickutz die or a petite zipemate die (there are other wafer thin dies on the market which i assume you could use as well) which becomes a shim to bring the die to the thickness of a sizzlits die and so making it possible to cut other brands on your machines.
They are made by sizzix so that you the consumer can get more use out of your sizzix and sidekick machines.
Directions for Use:
for the sidekick machine it is the same except that you do not need the sizzlits converter and you turn the handle.
Cut your paper to the required width and place onto your cutting mat,
Place the converter (black magnetic) into position,
Place the die face down into position on your paper,
place the Adapter over the die and pull down the handle.