Modular helmet and prolyvalant

I use this helmet for mountain biking and normal biking.
I was skeptical given the low prices and the severe lack of photo showing the helmet without the chin, but there is no fear. This helmet is of good quality, and the concept of power or remove the chin the top is really smart. When I am not sure of the route, I stop and fixed the chin.

However, for fans of DH-down, I do not think it's strong enough. Turn to a full helmets "whole" - inseparable.