Yellow zinc passivated for corrosion resistance. Single-thread, case-hardened PZD countersunk screws. Includes most popular sizes. Sizes: 3 x 12, 3.5 x 12, 3.5 x 16, 3.5 x 20, 3.5 x 25, 3.5 x 30, 3.5 x 40, 4 x 20, 4 x 25, 4 x 30, 4 x 40, 4 x 45, 4 x 50, 5 x 30, 5 x 50, 5 x 60, 5 x 70, 5 x 80 and 6 x 100. Sturdy case with removable plastic compartments