Blakoe ‘Energiser’ Ring, a device for urinary incontinence and erectile dysfunction (impotence), Sussex, England, Blakoe Ltd, 1960-1980

Made from Ebonite (hard rubber), this device was made to fit around the base of the penis, passing behind the scrotum and testicles. The ring is formed of two straight parallel sides and two curved sides. It opens on a swivel and is secured in the closed position by a recessed brass latch. Strips of copper, zinc and brass line the internal surfaces of the curved portions.

Invented in the 1930s by Dr Robert Blakoe as an alternative treatment for urinary incontinence, the Blakoe Ring™ was – and still is – sold as a form of electrotherapy for erectile dysfunction (impotence) and testosterone deficiency as well as bladder weakness. The idea is that, when in contact with the upper side of the penis and the lower side of the scrotum, the metallic surfaces produce a small electrical current that stimulates the genitals.

The product’s website boldly claims it to be "the safest and most effective device ever invented for the improvement of male sexual function" and says it may also help increase the production of sperm by cooling the testicles. The company recommends users adopt a well-balanced diet, moderate their alcohol intake, and stop – or greatly reduce – smoking to improve chances of success.

Erectile dysfunction is very common, and men are more likely to experience it as they get older. Stress, tiredness, and alcohol are contributing factors, but it can also be caused by a range of health conditions including high blood pressure, diabetes, high cholesterol, depression, anxiety or hormonal imbalances. The first line of treatment is often medicines, such as Viagra (sildenafil) that increase the blood flow to the penis. These are not suitable for everyone, however, and can produce unwanted side effects. Medical devices such as vacuum pumps (which also encourage blood flow) and penis rings (which apply pressure to the blood vessels supplying the genitals, causing the blood to leave more slowly) may provide effective solutions for some people.