CNC-machined aluminum upper surprise cap for surprise human body made from premium lightweight Swiss 7075 T6 aluminum. Ebony color. Group of 2. top of the aluminum limit features a tiny vent opening that makes surprise set up extremely predictable and simple, since extra shock oil will escape through this vent opening making sure only the proper number of the oil is in the surprise construction. Machined inside ridges confirm proper placement and sealing for the super-soft silicone membrane.