1/2 inch Strain Relief Cord Connector
Straight; Body Material
Die Cast Zinc
Gland material-unknown
Bushing-Blue Nylon

The items are new, out of box.
The retaining collar has S 1/2 L.
I don’t know the manufacturer or whether the rating is for liquid, EMP, or RFI

The photograph shows the 10 connectors for this sale.
One was taken apart to show the features of the components of this item.