This is the DUI Replacement Drysuit ZipSeal Latex Neck Seal for Drysuit Diving Features: Easy to install Can be installed on any DUI drysuit Can be Cut to Size NATURAL RUBBER has many good characteristics. It has high resilience, good compression set, good roll building behavior, and molding properties, very good friction surface, but not a fine smooth surface when ground, high tear strength, low crack growth, usable for ketones and alcohol, and good low temperature properties.