This is for a bike that has an Acros Ai4i upper headset cup and an Ai52 lower headset up, i.e for a tapered fork and headset.
You will receive
1 x Upper AC3041
(Also know as MH-P03K / ACB337)
30.15 x 41 x 6.5 – 36/45
1x Lower AC4052
(Also know as MH-P16)
40 x 52 x 7 – 45/45
Please not this kit does not come with the R2 compression ring used on the modern version of the eadset. You can reuse your current ring if still in good condition. Or you can buy these rings online. Please check your current headset to see the ring.
These bearings are nor Acros branded. They are selected from a quality supplier, with precision measurements, but at a much more affordable.