Carolina Gym Supply Black Hole MatThis mat is a protective cushion for the area where your in ground Tumbl Trak bed ends before your pit begins, The Black Hole. This mat is custom made for your space and can either fasten via hook fastener to a resi mat or transition past the concrete lip into a loose foam pit. The idea of the Black Hole Mat is to protect those gymnasts that miss their mark coming off the Tumbl Trak.