I posted this a couple years ago but was going through my collection and thought perhaps newer members might like to have a look. No logo, patent or trademark stamps. Only a tiny hand engraved number 228 that I almost missed. I believe it was part of Gillette's in-house review of proposed new products. Perhaps Gillette signed them out to marketing employees to examine and test prior to the initial public product offering. Employees were probably required to turn them back in to be destroyed but someone kept this one.