Control solution from Assure offers accurate results and is easy to use for at-home testing. A 0.5 microliter sample of blood is enough to produce results within 7 seconds. The blood glucose control solution is compatible with the Glucocard Vital, Assure 4 and Assure Platinum systems. The pack includes two bottles of diabetes meter control solution: level 1, with a normal glucose concentration, and level 2, with a high glucose concentration. The level 1 bottle has a blue cap and the level 2 bottle has a green cap for ease of identification. Each bottle contains 2.5 milliliters of glucose meter control solution to check whether your blood testing device is working properly. You may need to perform a test if you think you're getting incorrect readings or suspect you've damaged the blood monitoring device.