Ottoseal S18 is a high quality Swimming Pool Silicone. It can also be used in Wet Rooms, permanently wet areas. It's also a great silicone for use in the sealing of Jacuzzi seams and joints. Stocked in white, it is also available in box quantities of 20 in a couple of other colours. Silk Grey (Light Grey) and Grey (A darker Grey). Having double the amount of anti fungal material it works well with the amount of chlorine in swimming pools.