Red Sea ReefSense – Magnetic 4-probe holderRed Sea ReefSense Magnetic 4Probe Holder keeps your probes organised, correctly positioned and easy to servicehelping you get more stable readings and a cleaner sump layout. Designed for the ReefSense digital probe ecosystem, this holder securely positions up to four probes sensors so theyre not bouncing around in highflow chambers. That makes calibration, cleaning, and daytoday maintenance faster, and reduces the chance of cables pulling on probe