The Medeco eCLIQ Spark key is the first battery-free eCLIQ key that generates its own energy. It opens doors with self-generated energy solely from the key, making the cylinder and key completely power self-sufficient. The energy required for the locking function and for checking access authorizations is generated by the key during insertion into the cylinder. Data is transferred between the eCLIQ locking cylinder and the Spark Key with the usual high level of protection against manipulation and sophisticated attacks of the CLIQ family locking system.