Mystim Slim Finn Urethral Sound, (Mystim Roundplug)

The Mystim Slim Finn is a 6 mm aluminium urethral sound with two built-in electrodes, so it can carry electrostimulation once it is connected to a Mystim stimulation unit. It is the slimmest of the Finn sounds and is meant for people who already have experience with sounding and want to add pulses to the stretch. On its own it is a smooth metal rod; the electrical part only comes alive when it's plugged in.

How a bipolar sound works

Along the rod are two conductive sections separated by an insulated band. Mystim places the poles a few centimetres from the tip, and the current flows between them, inside the urethra, once both have passed the opening. Nothing has to be stuck to the skin and there's no second electrode. Intensity, rhythm and program all come from the control unit you connect it to, such as the Tension Lover or the Pure Vibes. The sound plugs in through Mystim's Roundplug connection, and the stimulation unit is sold separately.

Before you try it

This is not a first sound. If you haven't inserted a sound before, get used to the process with a plain, non-conductive one first, so you already know your own angle, comfortable depth and how much lube you need. When you move to the Slim Finn, keep the routine you already trust:

• Wash your hands and clean and disinfect the sound before every use.
• Use plenty of sterile, water-based lubricant on the sound and at the opening.
• Let it slide in mostly under its own weight. Never push past resistance.
• Connect the cable only once the insulated band is past the opening, then start the unit at its lowest setting.
• Turn the unit off before you remove the sound, and withdraw it slowly.

Temperature and sensation

Aluminium takes on temperature quickly. Mystim suggests warming it slightly or chilling it before use to change how it feels; test it against your wrist first so it's never too hot or too cold. The metal is light, and with a rounded tip and polished surface it moves smoothly once lubricated. Stimulation units let you go from a slow tick to fast pulsing, so the sensation depends far more on the settings you choose than on the sound itself.

Cleaning and care

Clean it with water and a mild detergent after each session and use a skin-friendly disinfectant regularly. Dry it completely, then keep it in its own clean pouch or case so the surface doesn't get scratched. A sound should never be shared between people without full cleaning and disinfection in between. Check the polished surface now and then; if it ever looks scratched or pitted, stop using it.

Who this urethral sound isn't for

Skip it if you are new to sounding, if you have any urinary-tract problem or recent surgery, or if you have a pacemaker or implanted electronics. Mystim's general e-stim rules also apply: no use during pregnancy or with heart conditions.

Specifications

• Brand: Mystim, Finn urethral sound range
• Material: polished aluminium with insulated section
• Diameter: 6 mm (the slimmest Finn)
• Length: about 15 cm, as listed by the supplier
• Electrodes: bipolar, two poles near the tip
• Connection: Mystim Roundplug; requires a separate e-stim unit

Browse compatible units in our Mystim collection and read our guide to safe BDSM play before trying something new.