Magnetic Actuators Littelfuse Magnetic Actuators offer various grades of materials, including ferrite (ceramic), AlNiCo, and neodymium iron boron (NdFeB). These Magnetic Actuators are packaged in shapes similar to the relative mating sensors and are available in rectangular and cylindrical shapes. Littelfuse Magnetic Actuators feature a maximum size of 28.57mm x 19.05mm x 6.35mm and +105°C to +450°C operating temperature range.