This is a new 8 piece Whitworth Combination wrench set.

Sizes: From largest to smallest:

9/16W = 5/8BS
1/2W = 9/16BS
7/16W = 1/2BS
3/8W = 7/16BS
5/16W = 3/8BS
1/4W = 5/16BS
3/16W = 1/4BS
1/8W = 3/16BS