Despite the product photo, product does *not* measure UV intensity (uW/cm2), only the much less useful UV index (0-9 scale).
Furthermore, the product is not very easy to use, requiring complex combinations of the two device buttons to be pressed to activate different displays / features - this is coming from a computer programmer!
Once the battery is inserted, the device never shuts off, the screen will be on until the battery dies.
The plastic body of the product is made from a material which constantly feels greasy - it feels horrible in hand.
Sadly, there are very few consumer UV measurement devices (I did research before buying this item), and most do not seem of any real quality - and the step up to industrial products is undesirable (these devices are larger and much more expensive).
I have also been informed by the seller that the manufacturer is no longer contactable (gone out of business?)
In short, I would not recommend buying this product.