Bluelab PROBPHLEAP Leap pH Probe, Replacement Probe with BNC Fitting, use in Soil, Coco, Rockwool, Root Zone and Solution, Easy CalibrationReplacement pH probe for Bluelab meters used for measuring in media (rockwool, soil, coco, etc.) Fully waterproof probe is easy to clean and calibrate Gel filled with double junction reference to improve lifespan Lab quality; Probe holder included; BNC fitting with 6. 6ft standard cable Supplied by Bluelab, the industry leader in hydroponic testing equipment; 6 Month Limited Warranty with proof of purchase Bluelab PROBPHLEAP Leap pH Probe, Replacement