Offers a 1 1/4" Hole . The Outside Dimensions are 3.78" By 2 1/8"
Note:Need To Drill Or Saw Two 1 1/2" - Through A 2" Hole. Many Cars Come With This Size Of Hole Already. Then Deburr The Firewall, Center This Bracket In The Hole And Mark The Holes.Then Drill Two 1/4" Holes And Install Bracket Via Supplied Bolts.