Cando Accu-Force band, 5-piece set, 4 foot, low powder (yellow through black) Cando AccuForce is a high quality latex band. Achieve specific repeatable and measurable levels of performance with each rep. The patented indicators show exactly when four levels of elongation are reached. Each level of elongation corresponds to a specific amount of applied force. When a level of force is reached the indicator shape will have completely morphed from a rectangle to a square [Force = Rectangle Squared]. Lightweight, portable, and measured repeatability! 5 progressive levels of resistance. Each level has four indicators that show when 50%, 100%, 150% and 200% elongation have been reached. Cando AccuForce allows for 20 measurable levels of progressive exercise therapy, instead of 5 levels. [4 levels for each of 5 resistances]. Cando is licensed to use the Thera-Band color sequence, so resistance level is easily identified. Product photo may not exactly match the product offered for sale. Please refer to the product des