A point of sale terminal (20) having a reader assembly for reading a data card (48) having data stored on at least one data track thereon. The terminal includes a housing defining a guide slot (29) location for the data carrier and a transducer for detecting data stored on the data track. A removable guide element (23) is mounted to the housing at the data carrier slot location. This guide element (23) has at least a bottom wall portion (39) defining a bottom guide surface of a guide slot for the data card and one major sidewall portion (37) defining one side guide surface of a guide slot (29). An access window (50) is formed in the major sidewall portion. A mounting arrangement mounts the transducer at a prearranged location with the access window for accurate detection of data stored on the data track as the data card (48) is manually swiped through the guide slot (29).