FC relaxometry performed with electromagnets operating at a maximum field of the order of 1 T is a powerful method to probe molecular dynamics but the absence of high resolution prevents site-specific investigations as commonly performed in NMR spectroscopy. An alternative that preserves the high resolution and sensitivity of high-field NMR is to use the stray field of a high-field magnet as the variable magnetic field. High-resolution (HR) relaxometry consists in polarizing a sample and detecting the NMR signals at high field. The sample experiences lower fields between polarization and detection times by shuttling in the stray field of an NMR spectrometer. A large range of magnetic fields is reached by simply varying the shuttling distance in the bore of the magnet. In this way, it is possible to measure longitudinal relaxation rates at low fields with the resolution and the sensitivity of high-field NMR. The availability of the relaxation profiles extended over 2-3 orders of magnitude of magnetic fields provides a sensitivity to longer correlation times, i.e. to much slower motions, than achievable with standard high field N relaxation measurements. High-resolution relaxometry has been used to determine site-specific motions on pico-to nanosecond timescales in proteins. The first application was performed by the groups of Redfield and Kern and allowed them to detect rigid-body motions in the β-hairpin and adjacent loops of N-terminal domain of the SARS (Severe Acute Respiratory Syndrome) nucleocapsid protein (SARSN), with a timescale of approximately 0.8 nanoseconds. These HR relaxometry experiments utilized a stepper motor-driven shuttle system to move the sample between high and low magnetic fields, replacing the previous pneumatic system, both developed by This setup allowed for controlled deceleration of the sample, avoiding issues like protein denaturation that occurred with the more abrupt deceleration of the pneumatic system.