How Long Is A Piece Of String?

[sandyRoe]

Or rather, how long should the piece in a Flymo be?

[woofgang]

they usually have a blade set into the edge to cut off the excess, so from the reel exit to the blade.

[sandyRoe]

Scrivens, I meant the stuff that does the cutting. I've just noticed the blade Woofgang mentioned so it will set itself.
TY, both.