Ravensburger Krypt Silver 654 Piece Blank Jigsaw Puzzle Challenge for Adults &ndash; Every Piece is Unique, Softclick Technology Means Pieces Fit Together Perfectly High quality components  Ravensburgers jigsaw puzzles for adults will bowl you over with premium quality, in terms of both content and material. Precision fit  No matter how large or small our puzzles, each is precision made so that every piece fits perfectly. Softclick technology  Individual pieces are so precisely made that you can actually hear a soft click when you fit a piece into the correct place. Long term quality - Ravensburger has been making products for the hand, head, and heart for over 130 years. SOFTCLICK TECHNOLOGY  Individual pieces are so precisely made that you can actually hear a soft click when you fit a piece into the correct place.