SRF04 Ultra-sonic Ranger module The SRF04 Ultra Sonic Ranger Module is a high quality ultra-sonic range finder, which can easily be connected to the microcontroller to measure or detect the presence of obstacles.   Using a 5V supply and drawing from 30mA typ. to 50mA max. the SRF04 can be connected directly to the microcontroller without the need for a separate power supply. Condition: As new, desoldered.