I’m not sure this is something dyson publish. More that there’s a lot of other information out there. They do highlight the total length of a machine. This is the example on the V11 store page.

This post might have the answer you’re after - Model Comparisons - Dyson Cordless Vacuums V6 vs V7 vs V8 vs V10 vs V11 vs V15 | Dyson Community.

Just to update anyone else that may need to know i went ahead and ordered, the wand length of part number 969109-XX = 690mm (its described as a short wand) my understanding is the V7/V8 wands are between 710mm-720mm

With two separate lengths, I’d have expected the description to host such information. You sharing it here is a benefit.