Benz 3-Button Smart Shell (also called Mercedes-Benz 3-Button Smart Key Shell or 3-Button Key Fob Case/Housing) is a replacement outer shell/casing for Mercedes-Benz smart key fobs that have exactly three buttons.
A plastic + metal replacement housing designed to rebuild or repair a damaged Mercedes smart key.
It contains the 3-button layout typical of many Mercedes models (especially W204, W212, W221, CLA, GLA, C-Class, E-Class, S-Class, etc. from the 2000s–2010s era).
The shell does not include the electronics — you transfer your original key blade, circuit board (PCB), battery, and transponder into the new shell.
From top to bottom:
Lock button (closed padlock icon)
Unlock button (open padlock icon)
Trunk / Panic / Alarm button
High-quality versions are made with good ABS plastic and a metal emergency key blade holder.