Your search for "effervescent tablet" revealed the following:

Sale price £30.96 Regular price £40.00 Sale
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Sale price £69.85 Regular price £90.00 Sale
Sale price £77.99 Regular price £90.00 Sale
Sale price £38.95 Regular price £50.00 Sale
Sale price £89.96 Regular price £130.00 Sale
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Sale price £89.69 Regular price £130.00 Sale
On Sale from £34.92 Regular price £40.00 Sale