What are the minimum legal dimensions required for a physical barrier to qualify as a valid Sutrah?

The Sutrah and Warding Off Passersby (اتخاذ السترة ودفع المار)

• At least 5 cubits high.
• At least one cubit high and as thick as a finger.
• Exactly the height of the worshipper.
• Thickness does not matter, even a thread is sufficient.