Buffer Piece reduces damage taken by its holder from an opponent's attack by 20, discarding itself at the end of the opponent's turn after being played, or immediately if the holder is Knocked Out. The Arceus wording adds the word Any before the damage reduction clause, but the underlying effect is unchanged.
The card debuted in the EX era's Dragon with art by Katsura Tabata, then was reprinted in Dragon Frontiers, again credited to Tabata. It returned in the Diamond and Pearl era's Arceus with new art by Ryo Ueda. Our catalog lists 3 printings.
Buffer Piece's two EX era printings, Dragon and Dragon Frontiers, share the Katsura Tabata credit and wording, while the Arceus printing brings a new illustrator, Ryo Ueda, and the minor Any wording addition.
The Dragon printing is Buffer Piece's first release
The Dragon Frontiers printing is again illustrated by Katsura Tabata within the EX era
The Arceus printing brought new artwork by Ryo Ueda
No, it added the word Any and refers to the card as this card, leaving the effect the same.
20 damage from an opponent's attack, after applying Weakness and Resistance.
From Dragon (2003) · 2 printings
Attach Buffer Piece to 1 of your Pokémon that doesn't already have a Pokémon Tool attached to it. If that Pokémon is Knocked Out, discard this card. Damage done to the Pokémon Buffer Piece is attached to by an opponent's attack is reduced by 20 (after applying Weakness and Resistance). At the end of your opponent's turn after you played Buffer Piece, discard Buffer Piece.
From Arceus (2009) · 1 printing
Attach Buffer Piece to 1 of your Pokémon that doesn't already have a Pokémon Tool attached to it. If that Pokémon is Knocked Out, discard this card. Any damage done to the Pokémon this card is attached to by an opponent's attack is reduced by 20 (after applying Weakness and Resistance). At the end of your opponent's turn after you played Buffer Piece, discard Buffer Piece.

Buffer Piece
Pokémon Tool
First printed in Dragon (2003)
Attach Buffer Piece to 1 of your Pokémon that doesn't already have a Pokémon Tool attached to it. If that Pokémon is Knocked Out, discard this card. Any damage done to the Pokémon this card is attached to by an opponent's attack is reduced by 20 (after applying Weakness and Resistance). At the end of your opponent's turn after you played Buffer Piece, discard Buffer Piece.