How to identify buffer springs and buffers?

[Kotacam]

Yeah maybe I said that backwards. Longer the spring the heavier… oops

 

[stage20]

I need to up my game on them as well.
Std, reduced power, extra power. Round, colored, flat. So many

I read the other day rifle spring has around 40 coils and is good till it goes under 12", then time to replace.
A carbine spring is in the high 30s and should measure at least 10" or be replaced. Please advise if this is incorrect.