Numismatists use the term “slab coin” to describe a coin that has been certified by a professional grading service. As an independent third party, a grading service can objectively attest to the condition of the coin and provide certification. “Slab” refers to the encapsulation of the coin in a sealed tamper proof holder by the grading service. We are proud to offer a selection of Slab Coins authenticated and certified by the highly respected American Alliance Coin Grading Service (AACGS).