I have three tv extension tubes for sale.
A 3.5" extension - a few set screw marks otherwise perfect condition - $37 shipped
a 3.5" extension - set screw hole is stripped - redrilled and tapped would make it perfectly functional $23 shipped- PENDING
a 3.5" that has been modified to a 3". This one was put on a lathe and turned down .5". It is the one in the middle. It is in excellent condition. $30 Shipped-pending
These are all the set screw type and threaded for 2" filters.