The Aquameter is a leave-in soil moisture sensor pen that can be left in the soil for continuous monitoring, unlike other moisture meters that need to be taken out after each measure Set includes 1 refillable watering sticks (green) - Moisture meter for house plants that has refillable replacement core - Each stick last for approximately 6- This soil aqua meter has plant water indicator that changes color depending on soil type - White indicates watering; blue indicates it's been watered