Mapei Mapesil AC Silicone is a water repellent & mould resistant formula silicone sealant that matches the Mapei Ultra Colour grouts perfectly. Solvent-free silicone for sealing walls and floors around baths and showers. Mould-resistant and high quality surface finish. For interior, exterior and underwater use. Bonds to ceramic, porcelain, glass and plastic. Highly elastic for expansion joints in tiling. Suitable for use in swimming pools, bathrooms, kitchens and showers. Matching grout available. Waterproof Chemical & Mildew-Resistant Highly Elastic for Expansion Joints, Available in standard 310ml tubes, they fit easily in most skeleton guns.