There are many finishes and diameters available. The sizes relate to the diameter of the head, shafts are approx 1/2 inch long. Samples can be supplied.
If you do not own a nylon tipped hammer make sure you wrap the head of your hammer to avoid damaging the nail head. The nail spacer tool is an extremely simple but helpful tool which holds the nails upright as well as enabling you to fix and space the nails neatly and easily.