All gaskets have been carefully engineered to ensure a water tight and lasting seal. It is made from vulcanized synthetic rubber with a soft rubber bulb and harder heal joined in a strong vulcanized bond. They provide an extremely strong and reliable flexible joint. Suitable for in ground or above ground applications. Manufactured from SBR, NBR, EPDM, custom material available. High resistance to water Ozone, heat, seweage, UV, andabrasion. Joint can be deflected and permit axial movement to compensate for thermal expansion and contractin.