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This set of rocker style keys may have a macabre name, but they will prove very useful for locksmiths and security workers as they have been thoughtfully designed and very nicely manufactured. Stainless steel, numbering 13 individual coffin keys to a set. Use them as you would any "tryout" or "jiggler" key - gentle turning pressure while applying rocking motion until success is achieved in turning the lock cylinder. These keys are effective on both wafer and (some) pin tumbler locks.