Object: SteriPen water wand

For travellers on a budget, the SteriPen is one of the handiest and most cost-effective gadgets you will come across. Here in the developed world, we don't often think about the fact that water from a tap just isn't safe to drink everywhere in the world. Nor do we think about the cost of constantly buying bottled water, which can be up to 2000 times more expensive than the tap water we would pay for at home - not to mention the environmental cost of all those plastic bottles.

So if you're planning an adventure in the wild and you fancy keeping your budget at a sensible level, you'll soon see the rather large necessity of having a good water purifier - be it for camping trips or jetting off to explore Timbuktu. And this particular water purifier is light, portable, and completely hassle-free. It essentially (and by essentially, we mean 'put very simply' because we didn't understand a word of the scientific explanation) uses UV light to sterilise water that may be contaminated with nasty bugs such as viruses, bacteria or protozoan cysts. In just 90 seconds, the wand can purify a litre of water, killing 99.9% of harmful bugs by stopping them from reproducing. Be aware though - it may kill harmful bugs and microbes, but it does not remove chemical toxins that might have entered the water from industrial runoff or similar contamination sources.

Though it might have a complicated explanation behind it, the wand is ridiculously easy to use. All you have to do is submerge the wand completely into no more than a litre of water, leave it for 90 seconds (or 45 for half a litre) and bob's your uncle. They've added a nice touch with the small screen tells you whether or not it's been successful - a happy or sad face - especially for the more technology illiterate among us. The wand uses solely UV light to sterilise the water, so you avoid the nasty chemical taste left in the water once it has done its job.

Problems with this device aren't exactly copious, but it's good to be aware of a few things before you venture out into the wilderness intending to source your own water for a week. It runs on batteries (rechargeable or disposable), which are drained relatively quickly. Although it's possible to buy a solar power battery recharger, if you're not certain of having sun make sure you have a back-up plan in the form of some spares. Cold weather will also affect its functioning, so it may need a little warming up before use, and won't work if the water you're trying to sterilise is frozen.

However, on the whole this device works wonderfully well, and is extremely good value for money at only £90, available from Amazon.

Price : £90.00