The Amazon version, however, is priced at $39.99. And while theirs does also have AM/FM radio capabilities and a blue tooth speaker, I'm good with Aldi's take on it for almost three times cheaper. You ...

Low-temperature indium hermetic sealing of alkali vapor-cells for chip-scale atomic clocks Abstract: We present a low-temperature indium hermetic bonding technique on wafer level without using flux, ...