Where can I find a charity to donate money for mosquito nets and fresh water?

wishfuhoenix asked:

Last year I found a website for a charity that basically “purchased” mosquito nets, water, blankets, etc with the donations. So, you knew exactly what the charity could get with the money. I didn’t have the money last year, but I do this year and would like to donate in my family’s name for Christmas presents.

Basically, saying each member bought a mosquito net for a needy family or something like that. Where can I find a charity that does something like this??