The Hydro-Bat was designed to fit on wheel heads that have bat pins spaced 10 inches apart on center. The hard rubber grommets cast into the underside of each Hydro-Bat will not swell or change shape and are sized to fit over a 3/8" diameter bat pin head.
Due to their smaller diameter, the grommets under the 8.5 and 10" Hydro-Bat's are spaced 6" apart and require the HBA Adapter to convert standard 10 inch pins to 6 inches. This adapter is made of sturdy polyethelene plastic and fits snuggly over the 10" bat pins on your wheel head. It has two upfacing 3/8" diameter bat pins fused in at 6” apart. The 8.5" & 10" Hydro-Bats fit onto these pins.
If you have a wheel head with pins positioned at 9" apart we make Adapter HB9A which will allow you to use our bats. If you don't have bat pins in your wheel, no problem, our product works great with a bat gripper or grabber which allows you to attach any kind of bat to a wheel head. Custom adapters can be made for any size wheel head or pin configuration.