To be honest I wasn't quite sure what I was looking for, I bought what I thought was right and that turned out to be wrong! The service and help via email was poor and unhelpful. I still don't understand how I ordered a BC base and ended up with B27 bulbs! Are they the same thing?! And then becoase I didn't know the make of the ceiling light I have they just said they couldn't help. So I have £11 of bulbs I have no use for. No offer of a refund or exchange. Basically they got my money so stopped caring! It's ok though, I bought some proper BC bulbs off Amazon for half the price and they work perfectly.