Meter with Heavy-Duty 8" (20cm) Probe. The Extech MO750 Soil Moisture Meter has an integrated 8 in. heavy-duty moisture probe which monitors moisture levels in soil from 0 to 50-percent and easy 1-handed operation. Meter features a durable, water-resistant housing with a large LCD display, data hold to freeze the readings on the display, and minimum/maximum function. Comes with replaceable moisture probe (MO750-P), 4 AAA batteries, probe sensor cap, and user manual.