These look like resistance demonstrators for physics labs; slide potentiometers. Those devices were made very hardy back then, and while they can easily be replaced by a precision bournes pot or a used Tegam resistance box, you have it why not use it? Just make sure the contacts are clean and be wary with the conductors exposed, its a shock hazard. Given the printed rating its rated for 425 Watts, when it was new. At 05:03 PM 7/28/2013, Joseph Gray wrote: >I know someone who has several of these old style resistors. Can anyone >tell me anything about them? Are they of any use? > >https://dl.dropboxusercontent.com/u/19599147/Resistor%20-%20side.jpg > >https://dl.dropboxusercontent.com/u/19599147/Resistor%20-%20front.jpg > >Joe Gray >W5JG >__ The information contained in this transmission contains privileged and confidential information. It is intended only for the use of the person named above. If you are not the intended recipient, you are hereby notified that any review, dissemination, distribution or duplication of this communication is strictly prohibited. If you are not the intended recipient, please contact the sender by reply email and destroy all copies of the original message. CAUTION: Intended recipients should NOT use email communication for emergent or urgent health care matters.