The suction cups are a revamped version of the twist cups. They can be used on any part of the body. By pressing the rubber suction cup, the cup sticks to your skin. The harder you press, the tighter it sticks. The suction cups come in 5 different sizes: 25mm, 35mm, 45mm, 50mm, and 55mm, and are offered in a pack of 2 pieces.