These are Hyundai / Kia Smart Key shells
Buttons
2 buttons
Lock + Unlock
2-button Smart Key shell
Middle
3 buttons
Lock + Unlock + Trunk/Hatch (HOLD)
3-button Smart Key shell
Right
4 buttons
Lock + Unlock + Trunk/Hatch (HOLD) + Panic/Horn (red HOLD)
4-button Smart Key shell
It is the outer housing/case only (black plastic body + silver/chrome trim + button pad).
Inside it holds the original electronics: circuit board, battery (usually CR2032), and transponder chip.
A small mechanical emergency key is normally hidden inside the fob and can be released when needed.
Hyundai: Elantra, Sonata, Tucson, Santa Fe, Veloster, Accent, i30, ix35, Kona, Genesis, etc.
Kia: Sportage, Sorento, Optima/K5, Rio, Soul, Cerato/Forte, Sportage, etc.