Thomas 1087 Traceable Giant Digits Radio Atomic Clock, 23/122 degree F, 16-1/2" Length x 10-1/2" Width x 1-3/4" Thick Accurate atomic clock Receives NIST signal Date, day, temperature, and humidity +/-1 degree C accuracy Measures 16-1/2" length by 10-1/2" width by 1-3/4" thick