The 3551/16 MC005 part of Alpha is a modular sealant from Dow Corning. It is a one-component, medium-modulus, neutral-cure silicone sealant designed for use in a variety of general-purpose joint sealing applications. It offers a range of features to make work easier, such as excellent adhesion, flexibility, and wide temperature range. Additionally, it cures quickly, making it a great choice for sealing windows, door frames, and other gaps.