Sets of 15 include the following dice in a display box:3 Arch'd4, 4 d6, 2 d8, 2 d10, d%, d12, 2 Balance'd20.
The Arch'd4 is a better alternative to the traditional d4; bigger, reads from the top face, easier to pick up, and easier to roll.
The Balance'd20 provides a more even distribution of results by ensuring all adjacent groups of 5 sides add to 52 or 53.