Specifications: Rate voltage: 12V DC Rate operating range: 10.5V - 16V DC Rate current: 100mA - 300mA Ultrasonic frequency: 40KHz Control moudle working temperature: -30 - 80 celcius degree Display working temperature: -20 - 70 celcius degree Sensor diameter: 18mm Installation mode: Drilling Sound: Heart beat type more recent alarm more rapidly About Shipping: All items will be shipped within 3 business days after the payment is received. Most times you will receive them within 8-12 days then. The specific delivery time is depend on circumstances.Any questions, please feel free to contact us During the shopping process, if you have any questions, please feel free to consult us, we will reply you within 24 hours, wish you a happy shopping Thanks for your cooperation and we'll make you feel satisfied.