Safe Seed can be purchased at amazon.com. It makes no durability claims.
Not much to say; it’s a copper sheet. At $16 this is the cheapest of all the devices ever tested, so it will be interesting to see how it performs.
Heat Stress Test
While there was some discoloration of the device, both engraved and stamped words are still legible. Note that I didn’t fill the whole device with words in order to minimize my time spent doing so.
Corrosion Stress Test
No data loss.
Crush Stress Test
It’s hard to tell from the photo but the engraved words are still faintly legible. No data loss.