From what I've seen, it looks like it's all-steel/alloy ...
... However, as others have said, I question the logic in calling it a 90Two. Picture
this ...
You: Do you have any 90Two's?
Gun Shop: Yes we have 92's
You: I mean the 90-two...
Gun Shop: YES, we have 92's!
You: To clarify, you have the 90-two, two is spelled out T W O
Gun Shop: I know how to spell TWO
You: Yeah but the model name actually has the numeric value 90 and the word TWO
Gun Shop: (Click)