What is this concave circle on the side of my milk jug? There's only one, there isn't an opposite shape on the other side.. : r/whatisthisthing

Product Description

Why Does Your Milk Jug Have a Circle in It?

Why Does Your Milk Jug Have a Circle in It? (It's Not Decorative)

This Is Why Your Milk Jug Has a Circle On Its Side

This Is Why Your Milk Jug Has a Circle On Its Side

What are the circles on the side of milk jugs for? - Quora

This Is Why Your Milk Jug Has a Circle On Its Side

This Is Why Your Milk Jug Has a Circle On Its Side

AClockStrikes3

This ornate cast metal piece. It is concave. Measures 13-1/2 x 7. Weighs 3 pounds. No maker's marks that can be seen, but there's a heavy patina on back. No moving parts.