Both flashlights used focused beam technology. This makes the area covered by the UV somewhat smaller but more intense. This allows it to work even when some other sources of light are present.
The smaller flashlight retails for $39.99, uses 3 "C" batteries and runs up to 60 before needing new batteries. It can be used in daylight if you are close to the stain, but works much better in dim light. Bulb life is up to 100,000 hours.
The $249 flashlight also used a focused beam. It has out put equal to lights selling for around $400. More convenient to use because it is lighter weight and turns on immediately (no warm-up time).
The light has a Maglight housing, uses 4 "D" batteries that last up to 8 hours before the batteries need to be changed. It can illuminate areas up to 100 feet away (only in total darkness). This allows the technician to inspect a moderately dark room while standing in the center of the room rather than needing to get with-ion a few inches of the surface he is inspecting. Bulbs last for up to 10,000 hours.
We are used to measuring the output of UV lights in watts of energy produced. With conventional UV lights most of that energy is actually heat. Because LED lights don't get hot, they produce the same amount of light with only a small fraction of the power. So don't be mislead by comparing the wattage of a LED flashlight with the wattage put out by a convention UV light.
Scott Warrington
PS Don't forget to get the amber glasses to
1. Protect your eyes.
2. Make the glow easier to see
3. Give you the cool CSI look when wearing them.