Magnetic resonance is well known in medicine as a non-invasive diagnostic tool. The patient is positioned in a magnet tube and investigated with radio waves to obtain slice-selective images. Contrary to x-ray tomography, the soft matter contrast is excellent in MR imaging. The same technique would be of great use for non-destructive testing of products from polymers and similar materials, if the object were not to be transported to the measurement device, but instead the device be moved to the object, and if the object could be positioned on the device instead of cut to size to fit the magnet hole. Exactly these problems were solved at RWTH Aachen University with the invention of the NMR-MOUSE (Nuclear Magnetic Resonance MObile Universal Surface Explorer). Depending on the particular design, two-dimensional images can be measured with it similar to looking through a magnifying glass at arbitrarily large objects but beneath their surface, and depth profiles can be measured with high precision from depth up to 2 cm. The device can be transported as hand luggage by one person and is suited for state assessment of rubber products and plastic pipes. It has also been used for investigations of old master paintings and to characterize the wound healing of skin in vivo.