This work was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, under award DE-SC0015947 (scanning SQUID imaging, implementation of millikelvin microscope) and the Cornell Center of Materials Research with funding from the NSF MRSEC program under award DMR-1719875 (SQUID and microscope design).

Here we provide the design files for a scanning superconducting quantum interference device (SQUID) microscope operating in a cryogen-free dilution refrigerator with a base temperature at the sample stage of at least 30 millikelvin. Details of the characterization and operation of this microscope can be found in https://arxiv.org/abs/2102.09588 .