The CD V-715 was the most widely produced of all the Civil Defense radiation instruments with a total of 567,457 instruments. As far as I know Lionel, Victoreen and Landers Frary & Clark were the only manufacturers of the CD V-715. Here are 3 examples of CD V-715s. Yeah, I know, they all look alike. There was also a Model 1 and Model 1B CD V-715.

"CD V-715 is a high range gamma survey meter for general postattack operational use. The ranges of this instrument are 0-0.5, 0-5, 0-50 and 0-500 roentgens/hour.

When properly calibrated, the response of this instrument is within the range of plus or minus 20 percent of the true gamma radiation dose from a Cobalt 60 or Cesium 137 radioactive source.

This instrument was designed for use by radiological monitors for the major part of their operation in the period following an attack. The instrument is primarily for surface monitoring survey but it can serve as supplemental equipment for aerial measurements. (continued below following photo)

The instrument consists of a detecting element, power supply, electronic circuitry to amplify the minute current from the detector, and a indicating meter. The detecting element of the the CD V-715 is an ionization chamber. (See photo above)

The CD V-710 medium range 0-50 r/hr gamma survey meter, which is similar to the CD V-715 except for it's range, and the CD V-720 high range beta-gamma survey meter have been replaced by the CD V-715. The CD V-710 will be phased out and replaced with the CD V-715 as states develop their own maintenance and calibration programs."
(From Radiological Defense Planning & Operations Guide SM-11.23.2 Revised March 1967 )