I buy from a major supplier so I can get multiples of the sizes I need in my shop for miscellaneous chores including tweakin with knives. They fulfilled orders with zephyr and I never went back. Zephyr is USA made and are excellent in quality. I used to vote Wiha until I found a domestic brand I liked and found affordable
I have the wiha stubby one that puts the bits all up inside the handle. It’s been going strong for several years.
As other have stated the Wiha bits are a great euro-brand. Felo is what I'm currently using for knife maintenance.