Does not fit model 4020,4010, 4100 or 4150. 

Please see the 2nd picture listed for measurements. 

Solid steel welded construction Universal Saddle Adapter allows rider to use the saddle of their choice! It increases the saddle height by 3.5". Over 6' tall? Want more leg extension? Just remove the FitDesk saddle from the post, install the Universal Saddle Adapter/ Extender on the post using the supplied hardware. Be comfortable and get more leg extension while you surf, read, work or game on your FitDesk!