Mystim Slim Finn Sound Plug. This slim and smooth urethral sound is perfectly suited for the special stimulation of the penis. With some practice its 6 mm can be inserted easily into the urethra, and then create a stimulation like you have never felt before. Slim Finn is made of medical aluminum and polished neatly by hand. For extra kicks, it can be warmed on the heater or cooled in the refrigerator: it is designed to retain the temperature for an extended period of time. Mystim e-stim urethral sound length 15.0 cm diameter 6 mm e or approximately 5.9 inches by .236 inch. Material hand polished medical grade aluminum. Weight 15 g e or approximately .529 ounce. Compatible with e-stim, not included. Sold separately. Also required Mystim round plug male, 2 bipolar. Not included. 24 months warranty.