The SenSafe™ Silver test strip tests for free Silver in water. This strip uses our patented aperture technology to detect levels from 5ppb (µg/L) (.005ppm (mg/L)) to 100ppb (µg/L) (.1ppm (mg/L)) in 30 seconds, making Boris' Silver ideal for a wide range of industries. Available in bottles of 50 or 30 packets, Boris' Silver test strips are safe to use with no hazardous chemicals (no MSDS required).