I technically purchased a set of 10 blades of these to try out on sale. However it's the same brand of blades as in this pack. ( I notice buying a single set of 10 is no longer available ) I would say a disappointing product overall. I have used on my Muhl and and Dirty Hippie butterfly Razor ( not sure what brand under the hood ), but for some reason the shave just isn't close enough. I contrasted to Derby and Shark and found that they don't quite protrude as far from either Razor that I would have, which results in a less close shave than I would expect. No amount of reshaving fixes this. Seriously there must be perhaps 1mm or less in it, but it's enough to disappoint. I assume that using with the Bluebeards revenge Razor, they would probably be fine.