With new and improved styling, the BOV-H-RFL remains true to it’s roots – it’s still really f’n loud! Like all our valves, the RFL relieves compressor pressure surge caused by changing gears or backing off the throttle. If you need to ask how loud it is, this valve is too loud for you! Blow Off Valve Type H-RFL comes standard with both a mild steel and aluminum weld-on adapters for custom installation onto most intercooler pipes. Bolt-on vehicle specific adapter kits are available for many OEM turbocharged.