Quill fitting of 22.2mm (standard 1") for threaded steerer. Clamp is 25.4mm with quill at 297mm tall (max extension 185mm). These stems are not for use with bolt-on (A-head) non-threaded steerers. One photo shows 'nutted' clamp model to illustrate stem with bars on bike - stem for sale here is similar but with concealed clamp as above.
