We are offering two sizes of Hydrodynamic systems to consider. The FB system can accommodate sizes from 4 mm to 26 mm, and the larger FT system ranges in sizes from 7 mm to 45 mm. The feed tubes are engineered to work with a 8mm range of material. Example is the 18mm feed tube could work with material down to 10mm diameter. These are approximate estimations and will be impacted by type of material and straightness of the bars. CNC Hydrodynamic system is 12.5' overall length and can accommodate material to a maximum length of 8.2'. We also recommend spindle liners with this item to maximize the support of the material and quiet & safe operation of the system.