Hi,
I think there is some issues on shelly's documentation about wall switch holder.
This is what shelly says :
1 button Shelly Wall Switch :
- Relay holder 1 – Shelly 1 / Shelly 1PM
- Relay holder 2 – Shelly Plus 1 / Shelly Plus 1PM
- Relay holder 3 – Shelly 1L / Shelly Dimmer
2 button Shelly Wall Switch :
- Relay holder 1 – Shelly 2,5
- Relay holder 2 – Shelly Plus Series (upcomming devices)
- Relay holder 3 – Shelly 1L / Shelly Dimmer
4 button Shelly Wall Switch :
- Relay holder – Shelly Plus Series
And the relay sizes :
- Shelly plus : 41x36x16
- Shelly 2.5/1L : 39x36x17
- Shelly Dimmer 2 : 42x36x14
So we should have an holder compatible with shelly 1L and shelly dimmer, which are not the same size, and a specific holder for shelly 2.5, which is the same size as shelly 1L. It's a bit strange isn't it?