Abstract: A fastening device and a fastening system including two fastening devices. The fastening device includes a first part having a first engaging side and a second part having a second engaging side, and at least two sets of individual engaging members configured to engage each other. Each set of engaging members includes a hook member and a locking member. The hook member protrudes from the first engaging side and has an engagement side from which a hook protrudes. The locking member is pivotably connected to the second part and extends into a recess in the second engaging side. The recess is adapted to receive the hook member for engagement with the locking member, and the locking member is configured to pivot towards the hook member when the hook member is in engagement with the locking member and a force is applied from the hook member on the locking member.