It says 10cm as well on EDIT, but they don't have the shorter ones in stock either in 14,4mm.
I don't have the 100ml, but in my experience with 250ml and 500ml Ehle tubes this is usually measured to go to the middle from the tube & I don't think that half a cm longer will be a problem. I wouldn't try 11cm with a 100ml though.
edit:
They have a 10cm diffused stem of slightly cheaper quality here:
click me
It's still good boro-glass (I have one), buy the diffuser holes look drilled instead of punched and some are really close together. They don't ship to the USA, but I could order one and send it to you if you really want one (or ten).