Pocket (playing card size) Mini MK-II mini optical fiber spectrometer, equipped with 2048 or 4096 pixel CMOS detectors, has fast transmission speed and high spectral response in ultraviolet and near infrared, with a resolution of 0.1 nm. Its low stray light of 0.2% and fast response time make its data transmission speed as fast as 4.6 ms/amplitude, and its integration time is 30us-50s. Mini MK-II is mainly used in the field of OEM, and is used in the development of handheld spectrum application system.