Size 25 to 100mm. The same standard with Festo ADN series.
CAD 3D and download.
https://emc.partcommunity.com/3d-cad-models/sso/sfm-compact-cylinder-guide-rod-type-emc?info=emc%2Fcylinder%2Fcompact_cylinder%2Fsfm-series&cwid=2368