Thermoplastic polyurethane has a famous ancestor which it gets more commonly confused with, TPE filament. But this newer version is entirely different from its predecessor as it has higher abrasion resistance, greater chemical resistance, and lower shrinkage.
It is a serious multiuse flexible filament which has excellent layer adhesion.
TPU’s resistance to grease, oil, and solvents making it more useful for industrial applications such as medical devices, power tools, automotive instrument panels, drive belts, caster wheels, footwear, inflatable rafts and mobile phone cases.
It creates rubbery elastic parts, and the less amount of infill you use the more flexible your finished object will be. So, your end print will be a super stretchable object that PLA and ABS cannot print ever.
TPU also has a considerably lower shrinkage as compared to its ancestor TPE, so if you require accurate measurements post printing, it is wiser to stick with TPU. It is also UV resistant and has a better retention of its elastic properties at a lower temperature and higher print resolution than TPE, so it is more suited to making mechanical parts.
It works wonders with printers with two heads since TPU can add that additional layer of the rigid base material to create a soft surface.