Window stops

I would appreciate your assistance. I am not the original owner of my unit. I do not see any labels on the windows. Instead I see the word FIBERLUX imbedded on the window. On two of the windows I see the numbers 89-3 and on the other windows number 90-4. Am assuming those numbers are the window size. A few of the windows - IMG 1393 - have the window stop (see above photo). The other photo is the empty slot. I believe the window stop piece is about an inch. Thanks.