2xGarden Plant Testing 3 in 1 Soil PH Tester Water Moisture Hygrometer Meter

Humidity Range: 1-10 (1-3 DRY, 4-7 NOR, 8-10 WET); Relative light: 0-2000 Lux (0-200 LOW, 200-500 LOW+, 500-1000 NOR 1000-2000 HGH); pH range: 3.5-8 pH (3.5-6.5 ACID, 7 NOR, 7-8 ALKALINE). No battery required, easy and convenient to use.

eBay