Pros: It looks great and build quality is excellent. It's also very easy to use; just hold down the button and the red LED comes on. When it detects an RF ('wireless') signal, the blue LED flashes or steadily lights, depending on the signal strength. Easy!
It's also got an adjustable antenna (see 'Cons').

Cons: It's too sensitive! The adjustable antenna makes it slightly better, as it can be pushed in to dampen the response or pulled out to heighten it. Even so, to use it to detect hidden signals, you need to be very patient, and make sure you turn off all ISM-band devices that you expect to be there first, or you'll get a lot of false positives.
No sound response (a pitched beep would be useful).

Other Thoughts:

Bottomline: Hey, for the price, it's great for a first rush through when doing a site survey or just a wireless bug sweep. Something a bit more in-depth (and far more costly) would be necessary for anything more intense, though.
Overall, it's fantastic for the price!

Pros: This thing is idiot proof. Just one button. You can't miss what to press..

Cons: This thing looks scarily like some kind of detonation device. I'm sure customs and immigration of any country will take a long hard look if they find this in your luggage. Also, it came bare! No instructions or anything. I guessed that it functions by pressing and holding the yellow button. It's not immediately clear. So far I only see the blue LED lit up. What's the other LED for? I dun even know what colour is the other LED! By the way, how do you change it's battery? Unscrew all the 4 screws? hmmm....

Other Thoughts: I think the girls need this more. First of all, if it does what it says, it will help to pinpoint pin-hole cameras. Next, the little thing is so shiny it can double up as a mirror. Best gadget you can get a girl.. ha ha ha ha...

Bottomline: A little too expensive for something that looks and feels a little to weird. Dun go flashing it in a foreign country less you want to be round up for questioning...

Pros: This device allows to ensure there are no wireless signals around you. You can use it to look for wireless hidden cameras.
The blue led blinks on a weak signal and stays on for a strong signal.

Cons: This device is kinda useless in the sense that it doesn't show the frequency it is catching. With the proliferation of wifi you will always find a wifi signal around you and so this device becomes useless as the led always stays on

Other Thoughts: No real benefit of getting one unless you are looking for wifi signals. Very hard to use it to find hidden cameras

Bottomline: Get a better unit, like sku.3617

Pros: It does well his work especially in GSM band, where are most hidden transmitters (especially audio).
Operation is easy and intuitive.
The antenna lenght "tune" the unit on the various bands admissible.
Therefore is advisable to do more inspections with different antenna lengths.

Cons: The construction quality is bad.
I received an rough hand-made item (especially the box).
Furthermore, the battery was virtually empty.
However, this is acceptable given the cost.

Other Thoughts: Recommended for all those who want to find out if someone listens to them (or watch ...)

Bottomline: Hard to find another device that makes his work well at this price.