I am sure you are aware of the difference between the different Personna Tungsten blade so I'll post this for those who may be interested.
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The Tungsten blades on the left are the most sot after blades. Many people get as many as 30 shaves from just one blade. These are very hard to find and expensive when you do find them.
The blades on the right are also very good blades. In my opinion the won't last as long as the pure Tungsten blades. I believe they will last longer than the usual blades one would purchase.
These are also difficult to find, and expensive when you do find them, however, not as expensive are the pure Tungsten blade. IMO