Magnetoresistance  is the tendency of a material (preferably ferromagnetic) to change the value of its  electrical resistance  in an externally-applied  magnetic field . There are a variety of effects that can be called magneto-resistance : Also called magneto resistance effect. some occur in bulk non-magnetic metals and semiconductors, such as geometrical magneto-resistance,  Shubnikov de Haas oscillations , or the common positive magneto-resistance in metals. Other effects occur in magnetic metals, such as negative magneto-resistance in ferromagnets or anisotropic magnetoresistance (AMR). Finally, in multicomponent or multilayer systems (e.g. magnetic tunnel junctions),  giant magneto – resistance  (GMR),  tunnel magneto – resistance  (TMR),  colossal magneto – resistance  (CMR), and  –  (EMR) can be observed. The MR is deigned by our company are most advanced in its specification and can undertake various tests needed by reaseachers