The little racheting screwdriver I ordered arrived so I rode the E-bike over to the hangar and it worked fine. It's the only way to tighten four screws that hold it into place. I assembled the 115-01879-00 GTR 200 Backplate and 37-pin d-sub connector labeled "COM" from the WH-00134-1 RV-12iS Garmin Common Harness (VFR) because it was already attached to the bracket. I wanted to connect the d-sub connector labeled "XPNDR" and the BNC connector labeled "XPNDR" from the WH-00134-1 to the 011-02976-00 GTX 35R Backplate Assembly but I don't know what hardware to use. I'll consult the installation manual. I connected the 9-pin d-sub and BNC connectors labeled "GPS" from the WH-00134-1 RV-12iS Garmin Common Harness (VFR) to the GPS 20A . And I connected the 15-pin d-sub connector labeled "BATT" from the WH-00134-1 to the IBBS-12V-3AH .