Gauge Kit Includes 1/2 in. NPT Adapter; Mounting Hardware; Instructions For Installation,Mechanical Instruments Provide Trusted Accuracy While Being Simple To Install,Unique Three-Dimensional Dial Design Gives Added Depth And Style To Your Custom Dash,Mechanical Movements Provide Accuracy And Durability Even In The Harshest Environments,No Electrical System Required For Gauge Operation; Compatible w/ Every Street Or Race Vehicle