Put this on your finger and live out all your Wolverine fantasies!
Seriously though, such a simple bit of kit with an extremely effective use. Keep the dexterity of your finger whilst being able to inflict the lightest of grazes or the most dramatic dragging. We've heard of them being used on nipples, balls, thighs, shaft and feet - they're really versatile!
First ring approximately 2.1cm diameter, and second ring (closest to the prongs) 1.9cm. If you don't think your fingers are big enough, that's ok, as you can bend your finger to keep it steady.