From the product description, check product page for current description, price and availability:

• 【 HIGH ACCURACY 】 : ph tester has a sensitive electrode sensor ,simply press “ON”, It only takes a few seconds for your result to appear on screen.read accurate pH levels. The included detailed manual will show you how to get the best accurate and stable reading.
• 【AUTO CALIBRATION 】: The Ph Meter Has an Auto Temprature Compensation Feature That Adjusts to Water Temperatures and Water Quality to Give Ph Readings Almost Instantly. As Well, You Can Calibrate the Tester with One Touch Button Using Buffer Powder.
• 【WIDE USE 】: Ideal for Household or Laboratory Use, Suitable for Testing Ph Balance of Drinking Water, Pool, Aquarium, Ro System, Spa, or Hydroponics; Appropriate for Wide Range of Applications.
• 【99% of ACCURATENESS 】 :Up to 99% accurateness . The test value might vary with atmospheric gases and temperature. Note: Pls don’t add acid or alkaline drinks to adjust, it can’t make any effect by doing this.
• 【3 calibration packages】Let you no longer worry about whether the ph meter is accurate, the 3 calibration packages we give can help you test whether our ph meter is accurate.