Hydro-Tone Hydro-Bells: The Original Relaunched. Hydro-Bells are a yellow hydrodynamic bell with three-dimensional configurations designed to enhance and take advantage of the total resistance field of water. Bells can be rotated 90 degrees to change the resistance from medium to maximum by changing the drag surface area. While they maybe not as maneuverable as some of our more compact bells, these sure do pack a punch for linear movements, strength training and muscle toning/development.
