Tweak nipple suckers, another unique design from the Kink by Doc Johnson collection, create powerful natural suction for authentic sensations and engorgement that traditional clips can not provide. With a simple squeeze, the Tweak set fits perfectly against the skin and creates a strong seal for hands free fun. Just attach to each nipple and watch them swell through the visually stimulating sheer black material. Total length 1.75 inches, width 1 inch, circumference 4 inches. Materials Thermoplastic Elastomers TPE.