The CsIII 4310B from Microchip Technology is a Time and Frequency Standard with Frequency 5 MHz and 10 MHz, Frequency Stability ±1 ppb, Phase Noise -155 to -95 dBc/Hz, Short Term Stability 0.00085 to 0.012 ppb, DC Supply 24 to 75 V. Tags: Rack mount, Frequency Standard. More details for CsIII 4310B can be seen below.