Reliable, irreversible indicator for low temperatures. Suitable for frozen or cooled products as medicine, chemicals and food stuff. Activated by removing the safety strip. After exceeding the temperature the colour of the window changes into red. - Size (L x W): 35.55 x 17.78 mm, 5.5 mm thick. - Special made possible in the range of: - 20 to + 25 °C. Reliable, irreversible indicator for low temperatures. Suitable for frozen or cooled products as medicine, chemicals and food stuff. Activated by removing the safety strip. After exceeding the temperature the colour of the window changes into red. - Size (L x W): 35.55 x 17.78 mm, 5.5 mm thick. - Special made possible in the range of: - 20 to + 25 °C.