This Traceable® GIANT-DIGITS™ radio atomic clock, with ambient and remote temperature and humidity, has giant size digits to be viewed from anywhere with desk/wall mount. Clock automatically adjusts for daylight saving, leap year, and even the earth’s wobble in leap seconds. Maintains better than 1-second accuracy for 25,000 years. Radio signal from NIST’s Colorado atomic clock automatically sets correct time/date. Desk stand and wall mount supplied. Simultaneously displays both ambient and remote F/C temperatures. Shows date, 12/24 hour format, day (1087 only). Traceable to NIST-To assure accuracy an individually serial-numbered Traceable Certificate is provided from an ISO 17025 calibration laboratory accredited by A2LA. It indicates traceability to standards provided by NIST (National Institute of Standards and Technology). Batteries supplied, remote temperature module supplied. Size: 16-1/2 x 10-1/2 x 1-3/4-Inch. Ambient Temperature Range: 32.0 to 122.0°F;0.0 to 50.0°C. Remote Temperature Range -58.0 to 158.0°F;-50.0 to 70.0°C. Temperature Resolution: 0.1°. Relative Humidity Ambient: 10 to 90%. Relative Humidity Remote: 10 to 90%. Relative Humidity Resolution: 1%. WWVB Signal Reception Frequency: 60 kHz. WWVB Signal Reception Rate: Every 3 hours. Temperature/Humidity Ambient Display: 16 seconds. Temperature/Humidity Remote Module Display: 16 seconds. Temperature/Humidity Remote Display on Main Unit: 3 minutes. Remote Module Transmission RF Frequency: 433 MHz. Remote Module Transmission Rate: Every 3 minutes. Remote Module Transmission Distance: Up to 30m (100-feet). Digit Height: 4-3/4-Inch. Weight: 3-1/4lb. Control Company #: 1087.