The LNF-ISISISC4_12A from Low Noise Factory is a Cryogenic Triple Junction Isolator/Circulator that operates from 4 to 12 GHz. It has an insertion loss of 0.5 dB ( at 3K and 77K), an isolation of 60 dB, and a port match of 17 dB. It has been designed from ground up to meet the strict requirements of ultra-low temperature physics research. The gold plated OFHC copper body ensures minimum loss and that this loss reaches the lowest possible temperature to minimize thermal noise. The device is available in a slim coaxial module that measures 67.1 x 24.6 x 10.2 mm with SMA connectors.