Ravensburger Krypt in gold. 631 pieces. I didn't open the envelope, but I used the picture on the back of the box : r/Jigsawpuzzles
Amazon.com: Customer reviews: Ravensburger Krypt Gold 631 Piece Jigsaw Puzzle for Adults - 15152 - Every Piece is Unique, Softclick Technology Means Pieces Fit Together Perfectly
Krypt: Gold - 631pc Difficult Puzzle By Ravensburger - SeriousPuzzles.com
KRYPT GRADIENT 631 PIECE PUZZLE - THE TOY STORE
Amazon.com: Ravensburger Krypt Silver 654 Piece Blank Jigsaw Puzzle Challenge for Adults – Every Piece is Unique, Softclick Technology Means Pieces Fit Together Perfectly : Varios: Everything Else