144 Count Clear Cover SPI Calibration Labels, 1-3/4" x 5/8" with blue print on white background. Protect the integrity of your information with our Clear Cover Calibration Labels. The clear polyester cover has an adhesive back and is pre-positioned on one side of the label to seal down over the variable data you've entered. The durable clear cover prevents tampering and alteration, and protects the calibration information from spills, soils, and abrasion.