The Survival Still is designed to provide families with a source of pure, sterile distilled water during disaster situations. The Survival Still is a heavy-duty stainless steel water distiller that purifies water by boiling the water and collecting only the pure steam — a process called distillation. The result is consistently pure water, for years or even decades without the use of filters. Third-party testing has shown that the Survival Still is effective at producing high-purity water, even from ocean water.