I Need a Photocell

Hi everyone.
Many thanks for your help.
I ended up getting a LDR with:

Maximum voltage (vdc): 150
Maximum power consumption (mw): 100
Ambient temperature (°C): 25
Spectral peak (nm): 540
Bright resistance (10lux) (thousand ohms): 30-40
Dark resistance (Mega): 5
Response time (ms): rising: 20 falling:30

It's doing the job very well.
Job done.