This is an iconic Mewtwo EX from the 2012 Black Star Promo BW45, originally released in the Legendary EX Tin era, professionally graded ACE 8 (NM–MT).

This artwork is one of the most recognisable Mewtwo EX designs from the Black & White era and remains highly collectible due to:
Legendary Pokémon popularity
Promo exclusivity
Strong demand for EX-era cards
The slab is clean and secure, and the card presents beautifully with excellent colour and holo effect.