What are these metal balls, hanging from chains, on the back of this tank's turret? : r/whatisthisthing

What are these chain-ball things hanging under the turret of this

Approximately 2.5m tank like object. Appears to be a lid on top

What are the small balls hanging behind MBT turrets? - Quora

Metal ball with raised patterns. Has rivets on ends like it's sealed

What are the small balls hanging behind MBT turrets? - Quora

Is the M1 Abrams tank's main cannon protected by burly turret

Something made out of metal. The top part can be screwed off, but

What are the small balls hanging behind MBT turrets? - Quora

What are the small balls hanging behind MBT turrets? - Quora

A very heavy (~300kg) metal thing me and my friend found in a ditch

What are the small balls hanging behind MBT turrets? - Quora