'a New improved razor blade of the atomic age' was the slogan for these blades, they were proprietary blades that can be used with the Segal and Schaeffer twist-to-open razors. As all pre 60's carbon steel blades they are pretty rough to use, but such a cool item to have, and importantly, keep as templates to cut modern blades to suit/fit these cool vintage razors.
The box is still sealed and blades in great condition, price is per pack of five blades.
Note* For obvious reasons vintage razor blades are a lot harder (and more expensive) to find than vintage razors, and such items will come and go on our website, grab more than one pack if you could, one to try out and one for your collection, soon enough they may not be available at all!