We recommend this seat post! But is not necessary for the ISM saddles! The ISM saddles just fit your current system.
Certainly for proper tilt adjustment that is so important.
This pen has a stepless adjustment capability. This pen also has a low spring road.
Take a good look at the size of your current seat post! This goes with tens of millions. Usually it is stated on the pen itself (get it out and clean it). This is available with a diameter of 27.2mm.