The offspring of a cattle prod and an electrical lamp? It definitely looks like something left over from the Spanish Inquisition.
Invented in 1918, this device promised to stimulate the abdominal brain (I am not sure what that is, although men have long been accused of thinking with it). The device consisted of a 4.25 inch probe which was plugged into the wall and then inserted into the rectum. When plugged in, a blue light bulb lit up to tell you it was working to restore your manly vitality.
Plus, from the Museum of Erectile Dysfunction, which has several more scary things - this electrostimulation device from the 1880s may look innocuous enough, until you find out that the short cylinder goes up the rectum while the length of the longer probe is inserted in the urethra.
One has a positive charge, one has a negative charge, and together they pack a wallop intended to jolt the genitalia back into action.