Foam spheres are available in various styles as with foam pigs, including bare, criss-cross, silicon-carbide, wirebrush and plastic bristle. They are used for the same applications as standard foam pigs, however, they are able to negotiate some piping configurations that standard foam pigs cannot, and can be magazine loaded in specially designed sphere launchers for automated mechanical launching. Note: If you are familiar with using a particular style of foam sphere or you have used a foam sphere before, please feel free to place an order. But, if you have never used a foam sphere or are unsure if a foam sphere is the best pig for your application, please contact us to discuss in more detail. Since spheres only contact the pipe with very minimal amount of their sealing surface (approximately 15% of their diameter) because of their spherical design, they are more prone to losing seal while negotiating various piping configurations (i.e. elbows, tees, wyes, etc.), and can therefore becoming stuck, versus a standard cylindrical pig which is in contact with the pipe their entire sealing lenth (approximately 1-1/2 times the diameter).