ULTRA-BLUE-SEAL® Wire Harness System - Grote Industries Trailer Wiring and Communications Systems – Lamp Jumper Harnesses. Provide connections to marker and license lamps through weatherproof UBS plugs. Plug directly into multi-ring sealed receptacles in the rear sill harness. Standard Male to Standard Female Wiring & Communication Product Category - Grote Industries Corrosion is not an option for Grote Wiring products. Ensure a perfect connection for your entire trailer with Grote Wiring and Communication systems. Cut-To-Fit® Wire Harness Systems. Slim-Line Under Light Females (Cut-To-Fit®) Standard Male to Slim-Line Under Light Female.