iReturn Pro LUOWEI Optical Screen Fingerprint Calibrator, For Repairing and Calibrating The in-screen Optical Fingerprint Sensors on Various Android Smartphones. Function: It is primarily used to recalibrate the optical fingerprint sensor after a screen replacement or other repairs, resolving issues like lost fingerprints, an inability to register new ones, or general recognition failure. Compatibility: The tool is compatible with a wide range of Android brands that use optical under-screen sensors, including Huawei, Xiaomi, OPPO, Vivo, Realme, OnePlus, and Samsung devices, among others. Usage: The device works by helping align the physical fingerprint module with the software's recognition area on the new or existing screen. This process often requires accessing a special "engineering menu" on the phone to initiate the calibration procedure. Benefits: Using this calibrator ensures that the sensor functions accurately and reliably after a repair, which is crucial for maintaining the device's biometric security features.