lot of heavy gauge cable connectors Lenco LC-10 etc industrial electric wiring

Lot of old heavy duty electric cable connectors. These are a twist lock design and several are marked Lenco LC-10. And '1/0' and '2/0' I've been told that these are generally used for extending welding cables. But these can out of the estate of a man who was using them with temporary industrial lighting.

There are three pairs (or 6 pieces). They are untested and are well worn with tarnish and soil as shown.