TruSens-HC-SR504-Ultrasonic-Ranging-Module-TruSens-HC-SR504-p-The-HC-SR504-is-a-non-contact-ultrasonic-ranging-module-with-a-20-to-4000mm-range-The-module-includes-ultrasonic-transmitter-receiver-and-control-circuit-all-on-a-compact-circuit-board-p-TruSens-HC-SR504-Ultrasonic-Ranging-Module