Lets get this straight. You want a spare part for a mower but you have decided not to say what the make/ model is.
Start with a Gooogle search for "make model spares" (replacing "make Model" with your own details)and see if there is a parts diagram on any spares supplier site.
Flymo are pretty good in that respect but, of course, you decided not to tell us what your own mower is.
dsfdsf, October 2017