Hydro-Bats are made of Hydro-Stone which is 8 to 10 times stronger and more scratch resistant than standard plaster yet still absorbs water eliminating the need to cut your pieces off the bat with a wire. Available as either standard flat bats or contoured domed bats for reverse-throwing plates, platters and bowls. Hard rubber grommets are set into the underside, sized to fit over any 3/8" diameter bat pins.