Kits comprise of a single wad punch handle onto which screws a series of nine interchangeable punches the handles are blackened and punches heat treated and chemically blacked the handle should be struck with a hammer or mallet onto a wooden block the spring loaded plunger in the handle enables holes to be accurately centred and serves to eject the slug the metric set contains 5 6 8 10 125 16 20 25 and 32mm sizes the imperial set contains 14 516 38 716 12 58 34 78 and 1in sizes