Drop forge chrome vanadium steel. 72 Gear teeth for a precise 5deg. sweep. Low profile head for access in tight spaces. Triple chrome plated, fully polished. Lifetime . Metric set includes: 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, and 19 mm wrenches.