The Specific Gravity Control Kit provides a tri-level set of controls for a refractometer to validate its performance and verify test results obtained by manual or digital refractometers. This set of controls meet SAMHSA Q.A. requirements for refractometers used for the Federal Workplace Drug Testing Program. These controls are for use with refractometers only, and are not recommended for use with Axiom’s liquid SG reagent. The kit contains 1 bottle each of levels 1.002, 1.011 and 1.023. Stability and Storage: Unopened bottles are stable until expiration date noted on bottle when stored at 2-10 C. Opened product is stable until expiration date if handled and stored correctly.