FiloSeal+HD is a duct sealing system from Filoform UK that uses hexagonal tubes and a flexible silicone-based sealant to seal cable configurations and pipes within ducts. The sealant, MD+, is applied from a skeleton gun and cures with air to form a strong, gas and water tight seal around cables and pipes up to 110mm or 160mm in diameter, depending on the kit size. The unique hexagonal tube design allows for easy positioning and separation of cables while providing strong backing for the sealant.