This is a used wire pulling grip made by Crescent.
Lineman know what it is, either for use on the pole or in the bucket truck.
This is a large wire grip. It fits wire diameters 3/8 inch up to 3/4inch. 3/0-336 wire sizes
It operates very smooth.
The tool number onthis is 385.
If you have any questions, feel free to ask.