And this is a part bolted to the bottom of the shock, the unsprung section, as in not carried by the springs.
“Who failed at physics at school” - maybe this was Wise confessing? 
Aceman - An advantage is that you cannot forgot about the lock and damage a mudguard of a caliper as can be done with a disc lock. A disadvantage is extra unsprung weight, plus they don’t describe the locking mechanism at all, so not sure how easy it could be picked or broken. End
Read aceman quotes extra unsprung weight for the handle bar locks
Anything carried on a bike in “sprung weight” unless yo attach it to the wheels
Which isn’t a good idea
Aceman was talking about the Roadlok and the advantage of it over a disk lock i.e. you can’t forget and damage a mudguard etc. He then added the disadvantage (still on the same subject of Roadlok) is the extra unsprung weight which he’s correct in saying.
No one of is gonna talk about the weight of handle bar lock’s when it’s insignificant compared with the rider, fuel levels etc.
You seem to have misread his post.
It’s a lump of aluminium. I doubt it weighs fuck all.
A little bit more than feck all : 400g