This is a Preowned Mastercool Intella Sense II 55900 In Case . In Great Condition and has been Tested and Found Fully Functional. Not Sure how old the batteries are so they may or may not need to be replaced soon. Uses 2 C Size Batteries.                                                                                                         The Mastercool Intella Sense II Refrigerant Leak Detector #55900 is a highly advanced tool designed for accurate leak detection in HVAC systems. Featured in a protective case, this reliable device is equipped with cutting-edge sensor technology that ensures a rapid response to all types of refrigerants. It is perfect for detecting even the smallest leaks, making it an essential tool for HVAC professionals.