Mermet metal pendulum (brass). The Mermet pendulum is made of brass and gold-plated. It is approximately 3 cm x 1.70 cm and weighs around 25 grams. The chain is about 20 cm long. It is an ideal metal pendulum for energy diagnosis, but it is also very precise for any other type of consultation. This metal pendulum format is called Mermet because it was conceived and used by the French missionary priest Abbé Mermet, who first applied the principles of dowsing for the diagnosis of diseases.