Now °F/°C and 24 hour/7 day are switchable! Use these low cost recorders to monitor temperature in walk-in coolers or in freezers. No special sensing element is needed. IncludesLED digital display. Recorder includes pen and AA alkaline battery. ±2% accuracy. Chart size: 4" diameter (not included). The chart chosen will determine the temperature scale readings. Model SK4 without digital display also available.