It uses a reasonable mechanic structure, which allows the interface part to be always horizontal for a smooth loading or unloading of bottles. 

   Height-adjustable duct is a necessary transitional part between the  mechanical conveyor and the air conveyor. It is often located at the palletizer and the depalletizer, before and after the labeller. It adjusts its neck guide height for catching different bottles. The neck guide height adjustment range is 0-150MM. 

   According to the transport direction, line-beginning height-adjustable duct and line-ending height-adjustable duct.