What Our Gearhead(R) Experts Are Saying:"I installed the MK0 Upper Headset Assembly on a trail build where I was chasing the lowest possible front end, and the 4mm stack got me exactly where I needed to be without any spacer gymnastics. The triple sealing gives me real confidence heading into wet and muddy conditions where a lesser headset would already be showing wear."Stack height is one of those numbers that matters more than it sounds, and the MK0 Upper Headset Assembly from Wolf Tooth Components brings it down to 4mm without touching the sealing or bearing quality that makes a headset worth installing. Machined from 6061 aluminum at the Wolf Tooth shop in Minneapolis, and spending four times as long in the CNC lathe as the standard Premium Headset, it sheds 44% of the aluminum weight while adding visible machine paths that align with the rest of the MK0 component family. Three levels of custom sealing, including an o-ring around the steerer tube and a custom-molded upper lip seal over the bearing, keep water and debris out of the places that cause long-term damage. Enduro stainless steel sealed bearings and a matching MK0 stem cap and hollow bolt are included, making this a complete upper assembly ready to anchor a build that takes every detail seriously.