Gravity Flow Telescoping Protein Tube Galvanized metal with four feeding ports, adjustable feed flow. Telescoping feature allows mounting to feeders at various heights. Tube adjust from 24" to 34" in length, tube size is 4 1/4" by 4 1/4". Feed flow ports adjust from 2 1/2" to 4" opening by adjusting wing nuts. Mounting bolts included, mounts to barrels, hoppers, etc.