How Are They Measuring This Quill Stem?

[woodbine]

Just a quickie. Would be grateful if the experts on here could tell me how they arrive at their quill lengths in the link. Either 230mm or 300mm. Where are these measurements from and to.

Many thanks.

https://www.ergotec.de/nl/producten/vorbauten/sub/schaft-vorbau/produkt/eagle-2-tube-25-4.html

 

[Tail End Charlie]

It'll be the length of the bit that goes into your steerer tube. The vertical part in the photo. The "extension" they describe is the length of the piece to which your handlebar attaches.

 

[Illaveago]

It is an interesting question. I would have thought that it would be the distance between the centre of the handlebar clamp and the minimum insertion mark on the quill stem.
If we had one to compare we could find out how they arrived at their figures.

 

[rogerzilla]

Seatpost lengths are usually from rhe very end to the saddle rails, but about 2" is not usable because it's below the max height mark. Are stems the same,?