3-Pack of EasyPro Black Expandable Waterfall Foam Ready to use 20 oz Cans (3)Pack - 20oz per Can of Minimal Expansion Black Waterfall Foam Use to fill in cracks between rocks to prevent water from being"lost" over the waterfall Ready to use - Foam Gun not needed - Trigger will dispense foam in any position Improves water flow visually and black color hides foam in the shadows of the rocks Fish safe, non toxic formula - Dries in just 30 Minutes