That block of wood is Spanish cedar and is used primarily as a spacer to keep the cigar rows even. But its also used to help keep the cigars fresh and maintain the cedar fragrance acquired during aging. Heres a neat little tip you can put to use, too: The next time you finish a box of cigars, keep the little block of cedar wood and put it in your humidor. It will help your cigars age and keep your box smelling fresh. You can even “re-charge” the aroma in the block by giving it a light sanding every now and then.