This photo from the St. Petersburg Times shows an E-meter with the optional remote tone arm to the left.

The two "cans" in the photo are joined together by a plastic insulator insert, allowing both to be held in one hand for solo auditing. This type of auditing is practiced only on the most advanced (and most expensive) Scientology levels, namely, OT III and Solo NOTs (New Era Dianetics for Operating Thetans.)

The remote tone arm attachment, sitting to the left of the meter, is used in solo auditing. The person holds the cans in one hand and uses their other hand both to take notes and to work the large knurled knob on the left side of the remote. The knob is geared to the dial on the front of the remote, so moving one also moves the other. Alternatively, the person could move the front dial with their pen.



What is metered auditing really like? Robert Kaufman spills the beans in his book Inside Scientology/Dianetics, which the Scientology organization tried to suppress.