The beckett 12-ounce black waterfall foam sealant helps to seal gaps in rocks and coping stones keeping them in place to direct water flow over rocks instead of under them; helps create a smooth appearance * The expanding foam will discharge a flat black color; gloves are highly recommended when using this product * Will cure in approximately one-hour and be ready for water flow in 8-hour * Safe non-toxic formula is fish and plat safe * Includes an easy to dispense tube