Note in the article description, what voltage your sensor needs. optional: cousing (which can also be 3d-printed).Female-Female Jumper wires ( US / UK), if not included with the USB converter.Serial USB converter ( US / UK) with 3.3V and 5V connection.Apart from the voltage the models do not differ much. Raspberry Pi Fingerprint Sensor ( US / UK).These are particularly suitable (also in connection with an Arduino). Some models can be used with both 3.3V and 5V voltage. Since there are different fingerprint sensors, which do not all work with 3.3V, a USB UART converter is recommended. The Raspberry Pi has two pins (pin 8 / GPIO14 and pin 10 / GPIO 15), but they work with 3.3V. These sensors were originally developed for the Arduino and can be read via UART. Accessories A USB TTL adapter with 3.3V and 5V voltage output can be used for many serial modules.