Solid-cast pigs are made of polyurethane, a highly durable material that resists wear, abrasion, and heat buildup. These high-sealing pigs are suitable for filling, dewatering, and applying coatings or chemical slugs. Because they are made entirely of urethane and are lighter than steel pigs, they can travel exceptionally long distances. Custom options include brushes, transmitters, and magnets. Different durometers (hardness levels) are available: softer urethane is better suited for high-sealing applications, while harder urethane is used for more aggressive cleaning. For urethane pigs, a transmitter cavity cover is installed at the rear of the pig so a transmitter can be inserted for tracking.