Vintage Metal Twist Gillette safety shaving razor Adjustable Fat Boy? Slim Boy?

Description

Estate sale find- I have no clue what type of razor it is. It is marked Gillette Reg US Pat off and on the inside says Pat. NOS on PKG. it opens and closes smoothly. It has a tiny spot of red on inside. Tried to get pictures of it but is light. Will need cleaning. Shipped with USPS First class mail and only to lower 48 states of the US.