In good vintage shape - see photos!
These may be the linear type -not much tactile or click feedback.
Some versions of these may be used in the following keyboards (from the excellent deskthority wiki)

• Some Chicony KB-5160
• Datacomp DFK-501F/502F (cyan for space bar, grey for enter)
• Datacomp DFK-555
• Datacomp DFK-777F
• Microweb Touch-1
• Olivetti M15 Laptop[11]
• Packard Bell XT keyboard (Sejin Type #: M7US02X-20, FCCID: GJJ4AKM-8700DE)[12]
• Sejin Electron EAT-1010 (cyan/grey for space bar)
• Sejin Electron SKM-1040 & SKM-1080[13]
• Tatung TCS-5000
• Sejin Electron SKM-1040