Our BC and SBC range of lampholders are both 2 amp rated so you can use a bulb up to 60W.
Our ES are higher amp rated at 4 amps so you can use a bulb of up to 100W. Most LED bulbs are now only a few Watts.
Please see our Light Bulbs FAQs for more details and help in choosing the right LED bulb.
The other consideration when choosing a bulb is what shade will be used. Generally the shade should have the same wattage rating as the bulb. So whilst you can rate the lamp holder this could change with the use of a fabric or paper shade and caution should be taken and advice taken from a qualified electrician.