The devices are characterised by high quality and long service life. When using spring pulls, the tool is pulled into the respective working position. This creates a progressive retraction force. After release, the tool automatically returns to the resting position. For models with additional locking (only TCN 9346 - 9350), the rope of the spring pull is gradually blocked when the rope is pulled out. By pulling the tool or rope again, the lock is lifted and the tool returns to the resting position.