Two of these fit together in the truck bed accessory port. Tested for compatibility with Rivian R1T (2022). Threaded holes for M10 or 3/8th bolts. Should be used with a bracket such as the "2-Hole Flat Straight Strut Fitting Bracket" sold at hardware stores.With four of these (plus 4 M10 or 3/8th bolts, nuts, and 2 brackets), you can mount strut across the ports of the truck bed to fashion DIY crossbars for well below OEM crossbar prices.Same as "Rivian Compatible Accessory Port Adapter - Bed", except the bolt hole is slightly offset to fit common strut holes. Offset is in the opposite direction to the port adapter"offset A".