6 in 1 TDS Meter, TOC Meter, COD Meter, UV275 Meter, Electric Conductivity Meter and Temperature Meter Water Testing Kit features the most updated technology with high precision. Wide test range makes it fits multiple uses, tap water, well water, water purified by drinking fountains, bottled water, ground water, surface water (not sewage) and other drinking water COD and TOC refers to organic pollution and other hazardous substances. These types of tests can usually only be done in specialized laboratories, but our high end water testing pens can perform these functions. Normally TDS can only detect minerals and other dissolved solids in the water, and the TDS value alone cannot be used as a criterion for judging the quality of the water. The probe is a laboratory spectroscopy probe, the device power on prompts "calibrate within a week", in order to facilitate laboratory use scenarios. For less rigorous daily home use or outdoor travel use, weekly calibration is not required. If you accidentally measure into sewage, simply rinse with water. After a period of use, calibration can be performed using pure water. Tip: Use purified water for calibration, not mineral water or natural drinking water. There are 4 levels of water quality: Excellent , Good, Average and Poor.Allows one button operation, just turn it on and put meter into water, you can get stable and accurate data in seconds.With our 6 parameters all-round water quality meter to ensure healthy water quality and environmentally friendly water, to avoid the absorption of harmful substances and accumulation in the body. Especially for the healthy growth of kids and safe water for pregnant women A great gift to give! If you don't know some suitable gifts for elders, family members, pregnant women, friends, etc. Colour: White Material:Plastic Package Contents: 1x tds meter digital water tester Only the above package content, other products are not included Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.