This is one of the armored "scales" or scutes of the extinct Glyptodont, which was a giant armadillo-type animal about the size of a Volkswagon Beetle. It was covered in these thick, hard, scutes to protect it from predators. These once roamed Florida during the late Pliocene and Pleistocene periods (approx. 11,000 to 5,000,000 years ago). This specimen was recovered from the Peace River (Florida, Bone Valley formation, Hawthorn Group).
Refer to the photo. The black centimeter cube is shown for scale and is not included. You are purchasing the specimen shown.