Paper Thermometer TL1-160 1-Temp Thermolabel are designed to ensure the dishwashing water and other sanitizing processes have reached 160 F/71 C. Simply place the self-adhering labels in the sink and the white square will turn black as the temperature is reached. Has approximately 10-15 second response time. The square will not revert back to white, might help with keeping a daily log of temperatures. Has a (2) year product expiration. - Paper - Sold per pack; 24 per pack