The M16 and M18 helmets are fairly similar in appearance. The major difference is the chinstrap system. The M16 utilized the old M91 Pickelhaube chinstrap which attaches directly to keyed lugs which are riveted directly to the helmet?s skirt. The M18 helmet did away with the archaic M91 chinstrap system. The new design added chinstrap bails riveted.The so called M18-cut out helmet is one of the rarest of German helmets produced in both WWI and WWII. This authentic replica helmet is made of steel with rolled edges, a dark green matte finish and adjustable leather headliner and chin strap.