This is the card from Slot K of an IBM 3274 Terminal Cluster Controller from the 1970s. According to the maintenance manual, this is an EIA/CCITT Driver / Receiver. I of course have no way to test this, so it is being sold with no guarantees or returns.
Accepted payment methods are:
Cash (mailed in a secure manner)
Money Orders and Cashier's Checks
Personal Checks (expect a hold of up to 10 business days for clearing)