The strong metal give this sounding a tough look, and makes it easy to insert into the urethrae. An O-ring for easy (and delicious) pull out, combined with ridges for extra enjoyment? Sounding is exciting, because it's fairly unknown, different, risky and non-traditional. The urethra passes by particularly sensitive areas in the penis head and the G spot. Sounding stimulates these nerves directly, offering a great sexual impulse for those who dare. Remember: inspect / wash / sanitize / sterilize. Play safe!