This is a Lansky Stone holder for the DMD Diamond resin whetstones that can be purchased on AliExpress. Search for "DMD Diamond resin whetstone" in the AliExpress online store.
The hones come in 4 different grits, 1000, 3000, 6000 and an amazing 12000 grit, and the hone size is 70mm x 20mm x 11mm. They work well to sharpen any type of steel and will leave a razor sharp mirror bevel on a knife.
The hones can be pushed into the slot and swapped out with the other grit hones, or even glued in permanently if you prefer for each of your hones.
I suggest to print it with the writing side facing up, and with a raft + support.
Note : When Finished printing and cleaned up, use a 5/32 drill bit to slightly enlarge the horizontal thread hole, then just screw in a Lansky thumb screw into the hole to tap a thread.
Some more of my designs:
Up Fila PLA