This entangled photon source operates based on spontaneous parametric down-conversion (SPDC) and generates entangled photon pairs with customizable signal–idler wavelengths in the visible and near-infrared range. It supports free-space or fiber-coupled output, delivers pair rates in the tens of Mcounts/s range, and is driven by an integrated pump laser with a typical power of 35 mW and 1 nm linewidth. The source includes an integrated laser current driver and a USB control interface. Performance parameters are shared between terrestrial and space-qualified versions, while the CubeSat-compatible space version features a more compact mechanical design than the standard enclosure size, enabling integration into small satellite platforms. The source is suitable for quantum communication, entanglement distribution, and quantum optics experiments in both laboratory and space environments.