Check the listing for details. HM Digital C342 TDS and EC Calibration Solution, 342 ppm (NaCl), 90 ml Volume. Color: Transparent/Blue, Condition: New. Listed at 9.99 USD. HM Digital C342 TDS and EC Calibration Solution, 342 ppm (NaCl), 90 ml Volume Product Image Item Description Product Description TDS Meter NaCl Calibration Solution C-342. From the Manufacturer TDS Meter NaCl Calibration Solution C-342. Features NaCl calibration solution, available in 342 ppm or 1000 ppm Comes in lightweight HDPE plastic bottles Sealed with a coated foam liner Use the HM Digital TDS Calibration Solution (342 PPM) to periodically re-calibrate your HM Digital TDS meter or HM Digital Water Quality Tester This HM Digital TDS Calibration Solution is also known as Water Tester Solution andTDS Meter Calibration Solution The C-342 is NaCl solution (342 PPM) Payment We offer secure and easy checkout for all major credit cards through PayPal. Shipping We offer fast and free shipping to the continental United States. We do not offer international shipping at this time. We do not ship to PO Boxes at this time. Returns We offer hassle-free returns within 30 days of the purchase, no questions asked as long as the item is returned in the same condition it was received. Please contact us for a return authorization and for the return shipping address.