what dimmer switch do i need?

[nvb272]

i have a dimmer switch that has 2 wires connected into L2 and 1 into the top C no wire connected into L1 and no wire with sleeve, just like to know what type of dimmer switch is suitable

the dimmer is the only switch it controls 2 lights, are the two wires supposed to be in L1 does it matter that they both in L2

 

[sparkyspike]

It shouldn't matter them being in L2. It only really determines which way up to mount the switch, which won't matter with a normal dimmer.