Very high level, 10000ppm quat disinfectant test strips, up to 10000ppm. Fast response, <5 seconds for Super HDQ, Quat 4, GS 256, Barbicide. Limit spread of zebra mussels, whirling disease; Phytophthora sp.; lice eggs (nits). Test foot bath sanitizer levels for use in phytosanitary certification. Only $17.95 for 100 strips.