Jürgen Reiche, the designer behind the famous Siebenstein-Spiele brand of mechanical puzzles specializes in creating high-quality and unique puzzles, ranging from packing puzzles to trick boxes. Their puzzles are designed with great attention to detail and require problem-solving skills and logical thinking. The company values creativity, innovation, and sustainability, using environmentally friendly materials in its production processes. Siebenstein-Spiele also offers a wide range of puzzles for all ages and skill levels, from simple jigsaw puzzles to complex mechanical puzzles that challenge even the most experienced puzzlers. Overall, Siebenstein-Spiele is a brand that offers high-quality and challenging puzzles that are sure to provide hours of entertainment and intellectual stimulation.