These molds are made of Stainless Steel, providing a durable mold that won't break under normal use. They work great for creating precious little bath bombs or for embeds in more elegant and complex bath bomb creations.
As its made of stainless steel, the mold is resistant to corrosion, whether its due to water, abrasive materials or corrosive ingredients. The molds have the strength to resist the most vigorous tapping.
This is probably the last mold you will need to buy, no more plastic spheres that crack and break under normal use!