The Hydro-Bat Hump Mold is a bat that you attach to your wheel-head and use while throwing. The mold attaches to the wheel with two rubber grommets embedded into the underside of the hydro-stone. After placing the hump mold on the wheel, simply lay a slab on top of the hump mold. Think of it as throwing the backside of a form. You will still have to throw a foot by gathering clay from the slab, or by attaching a coil and compressing it to the back.
Because the Hydro-Bat is made of Hydro-Stone instead of the standard pottery plaster, it's full eight to ten times stronger than similar products. Hydro-Stone is a US Gypsum material containing cement and crystalline silica, so it's very absorbent AND very strong -- you will find the surface of Hydro-Bats to be scratch resistant, while the bats' water-absorbing properties fully eliminate the need to cut your pieces off of the bat with a wire.
Hydro-Bat Hump Molds allow beginners and professionals to consistently make forms with ease. There is a variety of forms and profiles within those forms. Just because these hump molds were designed to fit on the pottery wheel doesn't mean you have to use them that way - they make great hand-building molds as well.