Torque and Chrome

Help me identify a hand tool, please,? I have acquired a torque wrench. It says Adjustable Metal Handle Micrometer Torque Wrench: CDI 1501MRMHSS I have the Certificate of Calibration. My question is this: What is this used for? And if I wanted to sell it what would it be worth? Thank you for any information anyone can provide. I have original case, original paperwork, and NO attachments - didn't come with any.