Model B30S sliding tray is flat tray that comes ready for installation. The tray is mounted by inserting it into the recess in the counter from above. Ideally it should be used as an indoor counter unit for handing over flat items such as files, documents, passports and rolls of money up to 30mm high. Automatic lock at full extension on either side. Lock can only be released by the operator behind the counter by using the lever. It is not possible to reach through the hole while the flat tray is sliding or manipulate the mechanism.