Product features: 1. Automatic constant temperature and high temperature protection. USB plug can be connected to a mobile phone charger or power bank. 2. 26C constant temperature control. 3. Quartz explosion-proof material for safe operation. 4. Compact design with a 52mm long heating rod, approximately thumb-sized, for discreet use. 5. Operates effectively with water levels as low as 2cm. Suitable for both freshwater and saltwater aquariums, pet feeders, and small fish tanks. Product name: Mini heating rod Main body size: approximately 8.5 x 1.8cm Usage: Small fish tank, pet water dispenser Temperature control range: 26C constant temperature Product power: 10W Input power: 5V 2A Recommended water capacity: up to 25L Note: Use a 5V 2A charger for optimal performance. Chargers with lower current output may result in improper heating or display issues. This product is suitable for water volumes up to 2L. Multiple heating rods can be used in the same tank to increase heating capacity. For example, two rods can be used in a 4L tank. Only one heating rod should be connected per charger or power bank, even if multiple USB ports are available, to avoid heating failure or reduced performance. Material: Glass Color: Black Package Contents: 1 x Mini Aquarium heating rod Note: Light reflection and differences in display screens may cause slight variations between the color of the item in the image and the actual product. Measurement may vary by +/- 1-3cm.