Any big supermarket should have them. They're a good match for "normal" fish fingers (i.e. shit), but weirdly tiny. You need about 5 to make a fish finger sandwich.
I have an unhealthy attachment to these, to the extent that I ate all (10 in a box) for breakfast on Saturday (two and a half sandwiches, with slices of pickled cucumber.) I. Am. A. Pig.
Any big supermarket should have them. They're a good match for "normal" fish fingers (i.e. shit), but weirdly tiny. You need about 5 to make a fish finger sandwich.