This is the helpful reply I received from Jim on woodworkforums
"That is a Teknatool chuck, I forget the name it was sold under. It was designed for turning bowls from green timber and had bronze instead of steel jaws. Steel reacts with tanin in wood and produces deep black stains. The four...
I am new to woodturning and have just purchased a Teknatool TL1000.
It came with various attachments including this chuck.
The jaws are tightened by screwing in the threaded rim.
Can anyone help me identify it and provide any information about it.
Thanking you
Richard