NMR experiments with fast magnetic field cycling and parahydrogen-induced polarization were performed on a home-built setup based on a Bruker Avance HD 400 MHz NMR spectrometer . The setup includes a magnetic shield placed on top of the spectrometer bore that allows achieving ultralow magnetic fields down to 5 nT. The desired value of the ultralow magnetic field is set by adjusting the current in the induction coils located inside the magnetic shield. The sample is mechanically transferred between the detection zone of the spectrometer and the magnetic shield via a plastic rail driven by a stepper motor. We also utilized an additional Z coil controlled through a relay to alternate between 50 µT (Earth's magnetic field) and ultralow field. This type of field variation has a duration of 100 µs, while shuttling the sample from the spectrometer field to magnetic shield takes about 0.5 s.