SSND-4mm
Recommended for open bore options
The SSND-4mm is our slimmest urethral sound, with a continuous 4 mm (12 Fr) profile from tip to base and no expanding sections. It's built as a low-intimidation starting point, with multiple insertable length options to accommodate different experience levels and preferences.
Details
- Shaft diameter: 4 mm (0.157", 12 Fr) — uniform along the full length
- Insertable length options: 2", 4", 8", or 12" (51, 102, 203, or 305 mm)
- Base: Safety flange
- Configuration: Solid only — this diameter isn't available with an open core
Choosing your silicone firmness
For the SSND-4mm, Bob recommends #18 (Firm) or #30 (Very Firm). At only 4 mm, the shaft needs a firmer durometer than usual to hold column strength for controlled insertion, while still staying flexible enough to follow your body's natural path.
Color options
#18 and #30 are available in pure translucent silicone.
#00-20, #00-50, and #10 use a translucent white base and can be mixed with our standard colors.
Please note
The SSND-4mm is our thinnest sound and can be ordered in several lengths, making it suitable for users who want to start with a shorter option and work toward longer lengths over time.
Use appropriate lubrication and never force insertion. Stop immediately if you experience pain, bleeding, or significant discomfort. Inspect the sound before each use and do not use it if damaged.