Nut driver holder
SAE: 1/4, 5/16, 11/32, 3/8, 7/16, 1/2
Metric: 6, 8, 9, 10, 11, 12
10 bit holder

Made for the extra bits from a Husky 149pc mechanics tool set

If the holes are too snug use a 7.5mm or 5/16" drill bit