They are plastic, egg shaped and hollow. Inside they have ball bearings that roll around with the movement of the body causing a "vibration". Normally two are used simultaneously and are joined by a string. The string aids recovery. Inserted into the vagina they are, I am told, very stimulating to the user and of obvious end benefit to her male partner of choice.
Any "beep" would be the metal detector devices picking up on the metal of the ball bearings though I am told that nowadays one can also purchase electric versions that work on the same principle as a vibrator so the metal detector would pick up the metals used in the "motor".
Well done Wenchy for admitting to their use. My admiration for you grows daily.
