CZT10, for 10 piece tap index. Holds the following 10 US tap sizes: 4 - 40NC, 6 - 32NC, 8 - 32NC, 10 - 24NC, 10 - 32NF, 1/4" - 20NC, 5/16" - 18NC, 3/8" - 16NC, 1/2"- 13NC, 5/8"- 11NC Or (Does not hold both at the same time) holds the following 10 metric tap sizes: 3 x 0.5, 3.5 × 6, 4 x .7, 4.5 x 0.75, 5 x 0.8, 6 x 1.0, 8 x 1.25, 10 x 1.5, 12 x 1.75, 16 x 2.0. Each storage hole precisely sized for accurate, quick tool selection. Corrosion resistant, epoxy baked on coating. Secure, snap-lock steel cover. Rugged, heavy gauge all–steel case. Made in the U.S.A.