ESS is an exclusive presence and braking signalling indicator with a LED light installed in the back of the helmet. Emergency Stop Signal function: signalling of sudden braking by means of a LED light with high intermittence, Built-in triaxial accelerometer, Exclusive algorithm that calculates the acceleration, Adjustment of the braking sensitivity level, ESS system is unrelated to the braking system of the bike, as it analyses the acceleration sustained by the helmet independently. Compatible with: N100-5/PLUS; N104/EVO/ABSOLUTE; N87/PLUS; N70-2 GT/X; N44/EVO; N40-5 GT/-5/FULL