Provides a safe, leak-free way to run wires through firewalls and bulkheads and throw away those leaky rubber grommets! Daystars Firewall Boot is the BEST way to run wires, hoses, and other lines through your vehicles firewall. Simply drill a 1.25 inch diameter hole in the firewall and install the boot. Run your wires, trim the boot as necessary, and secure the assembly with a zip tie. Its that easy! Safely and cleanly run wires through firewalls and bulkheads. Protects wires from sharp edges and eliminates air and water leaks.