A fuel injection system having a high-pressure fuel pump and a fuel injection valve connected to it for each cylinder of the internal combustion engine. After that, the ferrule is held by inserting a cylindrical portion of the ferrule into a holding unit of a ferrule holder from the splicing end surface. Density can be measured directly, or calculated from sensor readings. Presented content may be actuable, and allow a caller to change the destination of a call, take advantage of an offer presented to him, redeem a coupon, schedule or queue a subsequent call, etc. These support structures are particularly well suited for applications in building walls or roof panelized systems as supporting elements.