This is the standard top pad that goes on the top inside of your S1 Lifer helmet, slightly taller than the shallower 2mm top pad.  It is compatible with both Mini Lifer, Lifer, Mega Lifer, Lifer Visor, Retro and Fullface helmets. It will stick to the top of your helmet with velcro and allow for a standard fit for those who want a standard fitting helmet.