Range:LOW: 0-1999us or cm HI 0-19.99ms or cm Resolution:LOW: 1us or cm HI 0.01ms or cm Accuracy:2 percent F.S Power Suplly:4x1.5V(Not included batteries) Temperature Compensation:0C-50C Operating Temperature:0-50 Operating Steps 1.Remove the protective cap. 2.Wash electrodes in distilled water, and dry it by filter paper. 3.Turn on by "ON-OFF" switch. 4.Put electrode into liquid which is to be test, and stir lightly. Wait until the digital is stable, Slide the [ or us] switch to "" or "us", read the final value. 5.After use, wash electrodes, put on protective cap. Quantity:1Pcs Colour:Blue Material:plastic Size:170x50x28mm Package Contents: 1 x Water quality tester Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is 1-3cm.