Removing headset cups from 44mm head tube
The park tool RT-1 is the original headset cup removal tool for 1 1/8" headset cups. 



The RT-2 oversized headset removal tool is the correct tool for 1 1/4 and larger cup sizes. 

That said, the RT-1 can be used, when directed carefully, on 1 1/4" cups also.  

In my opinion, Park is too liberal in stating what larger headset sizes the RT-1 can work with, but it isn't technically wrong. 

Recently manufactured RT-1 tools have more flare to the ends than the older RT-1 did, which may account for the difference as well. 

Depending on when and where you bought yours, you may have the pre-1 1/4" version. Either because it's new/old stock, or because it was used...