Roman Armor Breastplates WIthout backs?

[Pointer]

Here is another question I am researching.

From 1 a.d. to 90 a.d. was there any Roman armor Breastplates, Hamata, Lorica Segmentata, Squamata or Muscle Cuirasses that only covered the front and not the back that would have been standard issue or purchased?

I have heard that there was, but I have not found anything that didn't protect both the front and the back.

Does anyone have any info or pictures that would confirm such armor?

Thank you Patrick