This sourdough starter warmer is a must - have for home bakers. It features precise temperature control from 70 - 120°F (21 - 49°C) with a smart thermostat memory that retains your last setting. The 0 - 24H timer offers hands - free fermentation, emitting a buzzer and auto - shutting off when time's up. The upgraded PTC heating panel heats quickly and maintains a stable temperature, protecting the starter's activity. Measuring 6.42 in. D x 5 in. W x 0.7 in. H, it's compact and portable, with a 50 in. US plug cord and 12W low power consumption. Compatible with 24 oz. to 40 oz. jars, it's perfect for daily home baking. Beyond sourdough, it can be used for yogurt fermentation, butter melting, and more. However, note that the actual jar temperature may vary, and calibration with a thermometer is recommended.