General Tools DSMM500 Precision Digital Soil Moisture Meter with Probe Designed to measure moisture content of soil; ideal for commercial, agricultural and professional use Features heavy-duty 8-inch probe; has minimum/maximum memory and data hold Measurement range is 0 to 50%; measurement accuracy/resolution is +/-(5% of reading + 5 digits)/0.1% IP65 water resistance; CE and RoHS approved Sampling time 0.8 seconds; power source is 4 AAA batteries (not included)