Jerusalem-based startup Lishtot won a place on CNBC’s list of the 20 hottest startups of 2015 for its inexpensive, reusable green light/red light device that takes about two seconds to tell you if water is pure or contaminated.

“Lishtot products identify changes in water electromagnetic properties resulting from the presence of problematic materials in drinking water. Its TeStraw is a personal water-testing device that will allow anybody, from Manhattan to Kathmandu, to check their water for drinkability,” reads the entry.

“The organization has developed a mobile product, as well as an on-pipe monitoring device. The technology will give filtration assurance in real-time. The sensing systems show very high sensitivity and measures for heavy metals and problematic bacteria.”

The list is described as “a sampling of some of the hottest start-ups from around the globe that made the 2015 Startup Open competition’s list of 50 top contenders.” In September, Lishtot won first place in the Global Entrepreneurship Network’s StartUp Open 2015 competition for Israel.

The technology can detect bacteria, heavy metals and organic pesticides based on changes in the water’s electronic properties. Lishtot (Hebrew for “to drink”) plans to introduce TeStraw – a straw-sized pocket device retailing for less than $50 — by mid-2016, CEO Netanel Raisch told ISRAEL21c.

Later on, the company plans to introduce a box-like device that will monitor water on a continuous basis and alert to any possible contaminants, as well as a dedicated smartphone app to connect many water testing devices in order to build worldwide and local water-quality maps.