For the European market NIU chose the well-known Swiss manufacturer of ready-to-use GPS modules: u-blox.
A press release  of u-blox reveals that they use the standalone GNSS‑Modul MAX‑7Q, which is using a Multi‑GNSS technology (GPS, GLONASS, QZSS und SBAS), making sure that tracking will work in any part of the world, at any time, independent from a single satellite system.