These are fancy head upholstery nails with a patterned head. The sizes relate to the diameter of the head. All shafts are approximately half an inch long. Samples can be supplied.
If you do not own a nylon tipped hammer then make sure you wrap your hammer head with a piece of leather, vinyl or similar to avoid damaging the nail . The nail spacer tool is also an extremely simple but helpful tool to help you fix and space the nails neatly and easily.