Need help identifying. Roman Empire?

Just found this coin in my backyard and I'm very curious. 

Coin is 2cm in diameter. Looks like bronze. Sorry I don't have scales.

On one side you can clearly see a face. Most probably with crown. Letters are not readable.

On the other side I can see Aequitas. And letter “C” which makes me think it ends with “OPTIMO PRINC”

You can also search with the image filter!

RegularCoiner

You can also search with the image filter!

Believe me my friend, I did. I could identify it 100%

Image search in this coins will be no help.

I would try to do some searchs like “radiate” and try few filters

https://en.numista.com/catalogue/index.php?e=rome_section&r=radiate&ct=coin&im1=&im2=&tb=y&tc=y&tn=y&tp=y&tt=y&cat=y&ru=&ca=3&no=&v=&i=&b=&d=&ie=&u=&a=&dg=&m=np&f=&t=18-22&w=&mt=&g=&se=&c=&wi=&sw=&p=1

But it seems your coin is not on Numista catalog

I would guess late 3rd century Gaul/Britannia  antoninianus. Reverse looks like MONETA AVG, Moneta standing left holding scales in right hand. cf.  N#29952

See also Carausius: http://www.wildwinds.com/coins/ric/carausius/t.html