So I passed (in cross passes) without the tray, and I was forced to board the clipper to suck small pelottes moss and plant waste removed and reassembled.
The unit comes with two rolls: one émousseur and scarifier.
I apssé on my clay soil moistened in a position émousseur ca ventilate my young grass.
+ Additional fertilizers Sowing = greener lawn than ever!
Detail: no traction system but by the scraping effect / scarfification, the machine moves forward naturally alone. I even tended to retain for the effect "scraping" even more effective!