All Hoppe dummy handle extenders stock has been discontinued as of 1/2020 - LIMITED to existing stock 

Hoppe Dummy Handle Extension for fixed levers

When adding an extension it may require a longer Spindle. 

Maximum of 1 Handle Extension for Dummy handles, requires longer bolt

HOPPE Handle Extension for Dummy Door Handles
Length: 3/4 inch  (20mm)  
Spindle Diameter: 5/16 inch (8mm)
Colors / Finishes: 8 Standard to Match HOPPE Handlesets, some finishes have be discontinued

This is for the DUMMY, will NOT work for active or inactive door Hardware.

When adding an extension it may require a longer spindle. 

Extension adds 0.79 inches (20mm) to length of handle

A Maximum or 2 extenders may be used

Longer, custom extensions and Spindles  are available - Special order my  Handle Extension for 8mm Spindle, 3/4  inch  ( 20mm)  length. 

This is for the Dummy Only - has a square end  - Special order - 

Will need longer mounting bolt 2-3/4 inch;  # 7177655