You can enhance the feeling by screwing the sharp points inwards with the hexagon key (included with the product). The pinching of these needles on the tightened skin is an excellent balltorture-mechanism. The points are sharp but not that sharp so they'll pinch but they won't (usually) break the skin.

Features:

Length: 15.5cm
Diameter: 5,5cm
Width rings: 1,6cm