The small KI Hegar sound is the gentlest size in this pair, with 5 mm at one end and 6 mm at the other. It's the usual starting point for anyone trying urethral sounding for the first time.
Made from chrome-plated brass
Overall length of 8 in, shaped with a soft S-curve
Insertable at both ends: 5 mm (15 Fr) and 6 mm (18 Fr)
Rounded tips and a smooth change in width along the rod
Compatible with silicone and water-based lubricants
Clean it before and after each session, be generous with lubricant, and stop if anything hurts.
A 7–8 mm medium size is the next step up. Browse more from XR Brands.