HC-SR04/HY-SRF05 5Pin Ultrasonic Module Ultrasonic Distance Sensor for Arduino
1 x HC-SR04 / HY-SRF05 Ultrasonic Distance Sensor Module. 1 x HC-SR04 Test Board. HC-SR04 Test Board Detection distance: 2cm-450cm. TX is the serial port sending end of the module. RX is the module serial port receiving end.