For use in the Maker/Explore machines, you must first remove the Cricut Accessory Adapter from Clamp A on your machine. This can seem a bit difficult at first but it's easily achieved by pressing up from the bottom at the same time you lift up from the top. Below is a link to the official Cricut page on how this is done as well as a YouTube video depicting how to remove. Not to worry, the Accessory Adapter can be easily reinstalled for any other Cricut Accessories.