digital tds pen portable TDS meter
according to quantity
1. we have good after-sales service . we are online 24 hours the whole day .you can contact us any time if there has problem .
2. we can supply you picture modification service . our designer can modify picture for you according to your requirements .
3.we can print logo on the tds meters for you .
4.we send 2 replacement tds meters every 100pcs for the buyer .