If you're into sounding (or urethral penetration, if you prefer) you know that this practice isn't something anyone should go into without lots of prior research, time, patience and a great set of high quality tools. These are those tools!
Sounding is an extreme form of play that involves inserting a rod or plug up through the penis via the urethral canal. For some, it provides a completely unique sensation and lots of pleasure, since the head of the penis and urethral canal is jam-packed with nerve endings. Sounding is also used as a means to direct prostate stimulation, while some penis-owners get off on the extreme nature of sounding. In either case, it's not something to be done on a whim, so if you're interested, please do your research!
In body safe stainless steel, the 8 Hegar sounds are naturally extremely firm and quite weighty. Each Sound is identical in shape - there's a slight curve to each tip and lots of very subtly widening length in between. The smallest rod measures in at 8" (20.3cm) long and just over .11" (3mm) in smallest diameter, while the largest measures 8" (20.3cm) long and about .67" (1.7cm) in diameter. There are 6 sizes in between, so you'll easily be able to find one that suits your need, desire or experience level.
Always follow a meticulous cleansing routine before and after using one of these (or any) urethral penetration deice. The Hegar sounds' stainless steel construction ensures extra thorough cleaning - boil them or bleach them for reliable sterilization. Always use the highest quality lube with any tool that'll be entering our or your partner's urethra - the best option is a sterile surgical or medical grade water based formula.
Approximate sizing (all are 8" (20.3cm) long)