The Moisture Meter Can Be Pushed Right Into The Compostumbler Or Compost Bin To Accurately Measure The Moisture Levels Of Your Compost. You Can Then Adjust The Moisture By Either Adding Water If Too Dry Or Adding Dry Material If Too Wet.a Really Useful Tool In The Garden, The Moisture Meter Can Also Be Used To Check Houseplants & Hanging Baskets Ensuring No Under Or Over-watering.accurately Measure The Moisture Content Of Your Compostmoisture Meter Spike Measures Approx 8" (20cm)can Be Used To Check Houseplants & Hanging Baskets