Passive tightened after automatic rotary. This is designed for central driving reeling and unreeling equipment, especially for flange single end or both ends.
Specifications : 
3" Outer diameter : r75.5 mm
Expanded diameter : r79 mm/max
Inside diameter of paper tube : r76.2 0.2 mm
Remarks :
Other sizes of outer diameter such as 1" to 12" are available on request.