Experienced puzzlers know that it helps to sort the pieces–by color, shape, border, or whatever works for you. This set of 6 trays makes it easy. Sort, then shake to sift out the puzzle dust. (That's why the trays have sieve bottoms.) When it's time to take a break, the trays stack neatly until you're ready to return. About 8" diameter, 4" high when stacked.