XRAY ULP Composite Shock Parts. These are direct replacements for the X4 ULP aluminum shock absorbers, but can also be used with the T4 family when equipped with ULP shocks. These shock parts feature the upper shock cap with 2 vent holes in the top cap, instead of 1. This makes for a more predictable and forgiving handling and improves traction. Package includes two inner shock caps, two spring cups and two rod ends.