All industrial scientific calibration cylinders are manufactured to the highest quality standards and include NIST traceable blend techniques, analytical leak testing of every cylinder, certified component concentrations and clearly marked lot numbers and expiration dates. Industrial scientific calibration kits come equipped with everything necessary to keep your gas monitoring instruments operating accurately and reliably. Kits contain certified NIST-traceable span gases for safe, reliable instrument calibration. Complete kits are available for all installed sensors and include: convenient carrying case, non-refillable cylinders, flow regulator.