Crib Toddler

How many coils are in the Serta Nightstar Extra Firm crib/toddler Mattress?
Looking for a firm crib mattress to fiit Graco Sarah 3-in-1 crib. Recommendations appreciated.
I am unfamiliar with this mattress. I do not according to Consumer Reports ” On the whole coil count doesn’t matter”. It went on to say that padding and foam layers are what commonly failed not springs.
I prefer all natural or organic crib mattresses due to the chemical being used to make mattresses fire retardant. http://www.stlbeds.com/mattresses/firelaw.php
From crib to toddler bed!!
