It is a zabuton used by sumo wrestlers ranked in the elite makuuchi division. In the grand sumo tournament, the wrestlers sit on the zabuton waiting for their turns to step onto the sumo ring. It is also called a hikae-zabuton.
This is a relatively-large sized zabuon, which is filled with thicker cotton batting.
Since the sumo wrestler’s professional name is embroidered on the center of the zabuton, this zabuton is often used as a gift to a sumo wrestler.