"Delighted to have found one small enough for my washbasin!"
Looked everywhere for one small enough to fit my washbasin - plughole has 6cm external diameter (incl surround) and 3.5cm internal diameter. The small Lakeland one fits perfectly. It is much easier to find the larger ones to fit *baths*, but it is useful to have a spare. The large Lakeland one fits my bath plughole, which is 7cm/4.5cm. The strainers are hard at work trapping hairs and soap-slime which would have clogged the waste-trap. Glad to say that they really are of stainless steel, in contrast to some dull metal ones from a rival seller which I had to return as they rusted in days!