Pike flies with Dutch
origins.
They
were designed to be fished in canals and dykes which as you know are
not usually very wide.This
is probably just as well because the fly is 8 to 9 inches long and tied
on a 6/0 to 8/0 hook.
If you tried to cast this on an ordinary trout rod you would probably smash it within a few minutes. The sort of rods used are about 10' and 12/13 aftm.
Having
said all that they do work.
The basic materials are Fritz (for the body) and bucktail and any sparkly material mixed together , some have bead chain eyes and some not - the ones I saw were tied in a variety of colours and combinations
For the last word on these 'Big Lads' - they cast like a wet sock.