The Masterson Sta-Wet Super-Pro Palette Sponge Refill is compatible with the Masterson Sta-Wet Super-Pro Palette. The sponges are designed to be used in combination with the Masterson Sta-Wet Acrylic Palette Paper (not included) to provide moisture for the Sta-Wet system. The sponges are reusable. When moistened and used in the Sta-Wet system, the sponges keep acrylics and other water-soluble paints workable for days and even weeks. The Sta-Wet Super-Pro Sponge Refill includes 3 sponges. Made in the USA.