The 600-04 Water Quality Sonde with internal battery pack is designed for use with any single YSI optical sensor and features a built-in shallow depth sensor.
The 600-06 Water Quality Sonde with internal battery pack is designed for use with any single YSI optical sensor and features a built-in medium depth sensor.
The 600-08 Water Quality Sonde with internal battery pack is designed for use with any single YSI optical sensor and features a built-in shallow vented level sensor.