This steel chastity device not only will prevent your partner from completing a full, aroused erection, but the device includes a urethral insert. The flexible insert contours to the shape of the cock, has a hex nut lock (to prevent slipping out) and a metallic end to make sure it doesn't go further than necessary. There is also a thru-hole for urine or ejaculate. Note that the urethral insert can be removed, if you wish to not use it for a particular session.
The device is made of stainless steel, making it non-porous, hygienic, easily sterilized, and temperature sensitive. The base ring of the device is fitted with a rubber sleeve, to avoid pinching or discomfort.
All prices are in USD.