Those are Fivestar hubs.
Not many options for those hubs.
Here are the only options i found;
-@moon Gear drives
- @IDEA makes them for a great price
- @Janux-esk8
https://www.janux-esk8.com/product-page/pulleys-to-fit-bms-rockstar-pro-and-rockstar-ii-hubs
More info here
https://www.electric-skateboard.builders/t/mbs-fivestar-hub-pulleys/94069