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Lifestraw is the ultimate purifier. It kills 99.99%  of the bacterias and the 98.5% of the virus.

Its weight it’s only a hundred grams and can purify 700 l of water.  Its price is of only 3.5 €

Eliodomestic is the best way to desalt saltwater. It cans  desalt 5 litres of saltwater a day  and turn them  into freshwater.  It cost 50 $  but is so  useful . 

The paperator 2000 is an useful paper destroyer which destroys the paper and recycle them into new recycled paper. It only costs 40€ and it works with solar energy.

the ecologycal basket ball 
This ball charges an inner battery when you bounce it and at the end of the match you can use their energy to charge your electronic devices or other things. It only costs 30€