Bleed proof, nontoxic, clean and non-oily, Therapy Putty leaves no residue and won’t fragment, separate, stain or stick to skin. Six distinct colors reflect established standards in resistive exercise: progress from super soft tan to extra firm gray. Putty can be squeezed, stretched, twisted or pinched to meet a wide range of strengthening needs, or used to encourage heel strike and strengthen foot muscles. Combine colors to create custom resistance to meet individual needs. Nontoxic. Latex free. Available in Yellow, Red, Green, and Blue.