Sikasil WS-290 is a one-part, neutral-curing, ultra low-modulus silicone sealant that cures to a durable, flexible building sealant. It performs exceptionally well under dynamic conditions due to its ultra-low modulus, high extension/compression, recovery properties, and strong adhesion to most building materials. It accommodates long-term movement of +100-50% in properly designed joints and is particularly well suited for use in exterior insulation. Size: 295 mL Cartridge. Color: Black.