These are soft leg cuffs which allow just enough floatation to support the legs for aquatics, in particular, watsu, waterdance, aquahara or aquatic osteo  approaches which involve dynamic movement.  Some floats can be too thick and actually impede your movements or even overfloat the body, so these cuffs can be perfect.  They come in 2 sizes to fit most people (Sm: $40, Lg: $45)
 
They are made from XLPE foam (Cross-Linked Polyethylene)  which is resistant to the conditions in which we work and play (water, sun, heat, salt, chlorine) and the closed-cell structure makes them dry quickly.    The velcro material which receives the strap is soft preventing any abrasion on the skin and the holographic straps shine with many colors in the sun.  Remember that you are light!