Cozime Durable Mini Power-free Analog Hygrometer Humidity Meter for Indoor Outdoor Material: Plastic Humidity Range: 0% - 100%. This durable analog hygrometer is excellent for use in incubators, brooders, aviaries and cages. They are widely used in greenhouses and any other indoor / outdoor areas, or simply for home use. An easy to read water resistant unit that is accurate and durable.