500 super fine stainless steel cleaning balls with a 3 mm diameter in a 1 5/8″ plastic, snap-close case. Many decanters have hard to reach curves. Just pour some of these balls into decanter. Add a small amount of water. Swirl gently and as the balls make their way around the perimeter, they loosen sediment, stains and debris, leaving you with a sparkling shine. The storage case features a drainage lid that allows the balls to dry after use. Rinse and dry the balls for re-use.