Smooth-Cast 60D urethane casting resin is a semi-rigid plastic (has some flexibility) that is strong and very tough. Originally developed for high impact tooling (drop hammer punch), Smooth-Cast 60D also offers good abrasion and chemical resistance and is ideal for a variety of industrial applications.
Smooth-Cast 60D was chosen by oceanographers to make transponders that withstand deep ocean pressures and dynamics. As an added benefit, it was discovered that the Smooth Cast 60D also helped to repel nearby sharks!
Unbreakable and Unsinkable - Smooth-Cast® 60D ocean transponders.