The PAX Plus has a full sized 0.5g oven, which will need to be tightly packed to get the best experience. However, if you want to use less materials or are looking for a shorter vaping session, it also comes with a half pack oven lid which decreases the oven size to 0.25g.
The PAX Mini has a smaller 0.25g oven size, the same as the half packed Pax Plus oven, and does not come with any oven inserts which increase or decrease the size of the oven.