A helmet body with an outer shell and at least two energy management liners may include an elastomeric shaft, a fixed retainer, and an adjustable retainer. The elastomeric shaft has a head, a tail, and a plurality of frustoconical ridges disposed along the elastomeric shaft between the head and the tail, the elastomeric shaft being narrower at the tail than at the head. The fixed retainer has first opening large enough to receive both the head, but a second opening is smaller than a size of the head. The adjustable retainer may have an aperture sized to receive the tail and part of the elastomeric shaft. The inner liner and the outer liner are coupled together with the fixed retainer on one side, the elastomeric shaft extending through the fixed retainer, the inner liner, and the outer liner and the adjustable retainer around the elastomeric shaft on the other side.