Glass work

What is OOS in this Case? (Reversible Case)
Glass work is an OOS case
Aluminum work is an OOS Case
Plastic work is an OOS Case
PVC work is an OOS Case

Single line crisp description - Why this has to be OOS?
- Partner don't have cutting tool
-Helper unavailable
- Skill issue in cutting the glass

What is NOT OOS in this Case? (NON-Reversible Case)
Replacement of Glass is not an OOS case