These old-school style dice roll more true random numbers and look unique. See videos below.
These dice come UNINKED - which means you must take a ultra-fine sharpie pen and ink the numbers your self. The reason is cause normal dice are tumbled till the paint wears off the outside edges which ruins the sharp edges, so these can only be inked by hand. Is not hard to do.
Some dice also have some "flashing" or rough edges from being snipped off the mold. Again this is normally removed in tumbling process but since these are not tumbled youll need to take a nail file to them to clean them up a bit. Small price to pay for more true random dice.
Why Game Science Dice (percision hard edged) are special: