ISR Aluminum Modular BOV Flange Kit - HKS The innovative ISR Aluminum Modular BOV Flange Kit is comprised of two pieces, a coped and threaded base, and a threaded flange. To install this kit you will need to weld the coped and threaded base to your charge piping, then once welded, the flange can be threaded on, allowing you to install your HKS BOV. ** All ISR Performance Products are Designed for Off Road Use Only **