Digital Thermometer Sheaths (500 per Box) These disposable probe covers will protect the operator, patient and thermometer from cross-contamination. These sheaths eliminate the need to disinfect or sterilize thermometers, which helps avoid contamination for both the patient and nurse. Simply hold sheath at the arrows and insert the thermometer. Hold the thermometer and the arrow tab and peel back the blue protective cover. Peel away the paper backing and the thermometer is now protected and ready for use.