MAPESIL AC - Pure, mould-resistant, acetic silicone sealant with BioBlock technology for movements up to 25%. Revamp your home with ease with the MAPEI Mapeisil AC 318 Oyster Silicone Sealant 310ml. Backed by bio-block technology, this silicone sealant handles up to 25% movements while providing excellent mould resistance. It's highly elastic and perfect for sealing, filling gaps, bonding various surfaces together, and more. Transform your home with the Mapei Mapeisil AC 318 Oyster Silicone Sealant. This 310ml tube offers a superior solution for sealing, filling gaps, bonding various surfaces, and accommodating movement up to 25%. Its bio-block technology provides excellent mould resistance. Highly elastic for a durable, flexible finish.