Master Key 2.0

Try to free one of the four keys in this challenging new puzzle designed by Jürgen Reiche.
The original version is here.

Made in laser-cut wood by Siebenstein-Spiele. Based in Munster, Germany, Siebenstein-Spiele was founded in 1992. Although the company is mainly known for board games, Siebenstein-Spiele also makes many wooden puzzles, several of which have been designed by company founder Jürgen Reiche.