This is an adjustable height 4-way toolpost for use on a Taig Lathe. You can have up to four different toolbits mounted ready for use.
The bottom adjusting ring base raises and lowers the toolpost head with 0.025" per revolution precision.
This toolpost takes 1/4" conventional toolbits, or square gravers. Four blank HSS toolbits are included, and a hex wrench for the clamping screws.
Here is a review by Nick Carter of Carter Tools: