My boom mower has a piece of 1/2" lexan (plexiglas) bolted to the
ROPS on the back edge and bolted to a piece of 1x1 angle iron that is mounted to the fender. Top of lexan is mounted to the underside of the canopy. It protects me when the cutting head is up close to the side of the tractor (rear mounted but will come up close to the fender when turned to the side). There is a wall of expanded metal across the rear of my head between the
ROPS uprights, but I can't remember ever throwing anything into it, due to the amount of metal in the way (the arms/tank/etc). Probably a good idea also, but the lexan gets a workout when I trim trees along side the ditch.
David from jax