The Calibrated V-Lok System immediately and clearly indicates whether the correct cuff is being used. Genuine Velcro hook and loop fasteners are used to provide the optimal number of open-close cycles. The center of the baldder is clearly marked ont he inner and outer surface for correct application on either the right or left limb. The cuff material is a tightly woven, urethane coated, heat-set Dacron TM Polyester fabric. It is stain-resistant and dimensionally stable.