Feature: 1. For easy reading and recording, the instrument will lock the reading. 2. Intelligent shutdown function, power off automatically after 10 minutes without operation. 3. Use titanium alloy probe to measure water with high accuracy, avoiding the influence of water interference, ensuring more accurate measurement value. 4. Large LCD display, easy to view, durable. 5. Professional manufacturing, stable performance and high reliability. Specification: Condition: brand new Item type: TDS Test Pen Material: plastic Color: As picture shown Weight: Approx. 55g Product battery model: cell battery Batteries: 2pcs Product model: LR44 Battery capacity: 160mah Product Usage: 1. The basis for detecting the exchange cycle of the water purifier filter 2. Drink cleaning drinking water. Package List: 1 x TDS Test Pen1 x Instruction Note: Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering.