received ok thank you .I fitted it to my pond UV lamp but a problem with a fit internally in the filter box ( mechanical size was not OK ! ) I tried to modify the bulb fitment by reducing its size ( but it still was of no use to me , nothing..! you can do for me now) I took the risk choosing this product knowing i would have to make a modification to it which failed !. Please be aware the lamp holder was in no way at fault & I will NOT be returning it to you, ( G 23 fitting for the 2 pin lamp i OK Just mechanical fit to Blagden pond filter was the problem?