The Cs4000 from Microchip Technology is a Time and Frequency Standard with Frequency 100 KHz / 1 MHz / 5 to 10 MHz, Phase Noise -155 to -95 dBc/Hz, Short Term Stability 0.00085 to 0.012 ppb, DC Supply 22 to 75 V. Tags: Rack mount, Frequency Standard. More details for Cs4000 can be seen below.