This is a mat for your...junk...? Well your mahjong junk. We really don't know why it's call a junk mat, but we accept it and love it for who it is which is a durable, foamy mat with little trays for your point sticks that rolls down into a carry case.
Used in many major tournaments, this is a popular product among mahjong players. It also protects your precious mahjong tiles from chipping and cracking.