Tinksky Portable 3 in 1 Soil Tester Moisture Light PH Tester Meter for Outdoor Indoor Garden Plant Flower Grass Lawn Material: durable hard plastic and metal. Meter size: about 5*8*3.5cm. Probe length: about 21cm; Distance between probes: about 1.2cm. 3 functions in one compact soil meter - used to measure the moisture and pH value of the soil and the environmental light. Works with all soil types and is suitable for use indoors or out doors - simply place it in the soil, set to the setting you wish to measure and read the scale. No need for batteries. Easy-to-read scale indicator.