Sapling's new SBL 1000 Series gives you the answer to your wireless digital clock needs. Working in conjunction with the Sapling SMA Series master clock (with transmitter option), the SBL 1000 series integrated seamlessly with the SAL-2 series analog wireless clocks. Working on Sapling's 915-928 MHz frequency hopping technology, the digital clocks will receive and transmit the signal once a minute.