Wiring light switch

[jamoor]

I bought a remote control light switch today
I have taken off the original switch and there are 2 cables going into it, L1 and common, they are both red in colour.
on the manual of the remote controlled switch it says that you need to plug the live supply into one and the other into the other,
which is the live switch?>

 

[jamoor]

I took a risk and it worked well.
Now i dont need to get up to turn my light off, all for 12.00