Probably the best pump head adaptor on the planet.
Designed to clamp around the valve stem and pump up to 300psi, without needing to be held.
It will fit every disc wheel there is.
(If the valve stem isn't ridiculously long).
Comes with a spare rubber grommit and a hose clip.
Simply cut off the old one, slide the hose clip on and tighten up.
Fantastic quality and value - this does the job beautifully.