My store，ur best shopping choice.Features:100% brand new ，high quality ，excellent after-sale serviceThe electrode has been used(laid) for long time from the last calibrationThe electrode has been used in particularly taxing conditionsThe utmost accuracy is requiredSpecification:Batteries: 3 x 1.5V(AG-13 Button Battery，Not Included)Life: approx. 700hours of useAccuracy:±0.1pH(at200C/680F)Dimensions:150mm x 29mm x 20mmNet weight:123gOriginal box: YESPackaging size: 180*60*30mmPackage weight: 140g Color: YellowPackage Content:1 x Pen Type pH Meter1 x Screwdriver 1 x PH 4.00 substances (250ml)1 x PH 6.86 substances (250ml)Purchasing here， fulfill your dream!