This unit utilizes a Russian Geiger tube to SBM-20 specs to provide extremely precise radiation measurements of both gamma and beta radiation. It measures in Sieverts which are roughly the equivalent to 100 rads/Roentgens. (one Roentgen is equal to 0.0093296636656249 Sieverts. )
Background radiation in the United States generally measures around .9 to .14 micro-Sieverts/hr. That is .009 to .0014 micro-Roentgens/hr.
Geiger counters that use a Geiger tube are only good up to about one million-Roetgen/hr. So this device is not for measurements close to a dangerous source of radiation. But the nice thing about this meter is that when exposed to high levels of radiation, it does not blank out, go crazy or die.
This meter will give you peace of mind when a nuclear event is said to have occurred that you are not being fried by silent gamma radiation.
Dangerous radiation cannot be measured by any Geiger counter, not even a CDV-700. You need an ion chamber like a CDV-715 for that.
This meter seems to be as robust as the Russian meters out there, at a fraction of the price.
This meter also has functions to measure electrical field, magnetic field and radio frequency. You hold down the left button and the unit switches into the other mode.
There are other meters out there with this exact case, but they are not the same meter. This version has different software to accommodate the other measurements, and this also appears to have upgraded the units flexibility with higher level gamma radiation. It will measure up to about 10 milirads, which is outside the bounds of a standard SBM-20 tube. This meter is capable of handling radiation levels found in much more expensive meters.
If you remove the cover you could also direct measure for falling beta particles if we are told that radioactive fallout is out there.