One Aqua Pedic Bath Mat new never used

Brand is aqua pedic. Not threshold, only listed as threshold for exposure. This is the one that has never been used and has just been stored away. It has a little something on it as pictured that could probably be scrubbed off. It has been stored for several years. Since it’s been stored for around 8 years I don’t know if the suctions on the back are still sticky? Just something to keep in mind when purchasing.