Cards that have been professionally graded and sealed inside of a protective plastic case commonly called a “Slab”. A “grade” is a numerical value that a paid expert assigns to a collectible trading card after it has been thoroughly examined from every angle and determined that it is original and unaltered. The grade number corresponds to the quality of the card's condition. Most grading companies use the 1-10 grading scale, with a card graded 1 considered to be of poor condition and a card graded 10 considered to be of perfect condition. Cards that receive a high grade are considered by many to be the pinnacle of collecting and are highly sought after by serious collectors world-wide. They are often worth, as well as sell for, staggering amounts of money.