170
Just for counting? For speed also?
(lemmy.world)
Let us help you identify that mysterious object you’ve found.
Currently in CHALLENGE mode: If you've got something obscure knocking about, post a picture, and let's see how we do. Please prefix such posts with "CHALLENGE:" so we know we've got a fighting chance.
They are for counting vehicles. You cannot determine speed accurately without knowing the tire circumference
By that logic, you cannot tell how fast I'm walking without my circumference.