Really? That was my first thought, but the foam look threw me off. I remember how amazing it was to discover how simplistic mortars are. Back in '79, they had cloth packets (quilted-like) with gun powder that were perforated and you tore off packets of gunpowder to determine the distance you wanted. They were placed around the bottom, tapered end and when dropped in the tube there was a firing pin at the bottom of the tube that triggered the ignition.