WCS’S Quick Click Firewall Adjuster is the most economical and best engineered firewall adjuster ever devised for your 1979-2004 Ford Mustang. Featuring a built in self locking mechanism that allows for you to simply turn it to a desired setting and never worry about it again. Locks on every quarter turn of the adjuster. Large firewall backing plate to eliminate firewall flex and premature cable wear. CNC Machined from 6061 Billet Aluminum with an extra thick base for additional firewall support.