This is a double-edge (DE) safety razor that works with standard blades. If you've ever wanted to try shaving with a DE razor before spending the cash on a nice one, you can give this a shot for less than $0.50 of plastic!
I bought a cheap ($20) DE razor on Amazon a few years back, and the top piece of the head eventually broke after dropping it one too many times. It was easily fixable with a screw (https://www.youtube.com/watch?v=HpteMAfR49Y), but also gave me the idea to make a 3D printable version.
The top piece has two variants -- one all plastic with a threaded piece to attach to the handle, and an alternative one with a countersunk hole so you can fasten it together with a 10-32 screw. The threads on the all-plastic version may involve some trial and error depending on your print settings.
The handle prints upright and a raft or brim is recommended to prevent it from tipping as it reaches the top. A layer height of 0.2mm or less is best to maximize the detail in the knurling.
The two halves of the head can be printed on their sides, in which case, the upper half will require supports. Alternatively, it can be printed upside-down.