This boost elbow  installs on compressor housing in place of stock boost fitting, letting you control boost pressure levels with a simple allen wrench. On Dodge Cummins trucks, factory boost settings are about 22psi. These Cummins Holset HX35W HX40W & HY35W ALSO S300 AFTERMARKET turbos are capable of much higher boost pressures, ( 35psi or more! ). By installing this boost elbow ,you get the most out of your turbo, faster spool-up, lower egt's, and increased performance. ( WILL NOT WORK ON on 2001-2002 auto trans with turbo part # 3592811 OR any stock turbo newer then late 04 because the turbos are computer controlled and there is nowhere to use the boost elbow.  You will receive your Boost Elbow in about three days. This is a small but wise investment for your truck. Check out my feedback for this item & also how fast I ship.  It is very easy to install and will take about ten minutes, detailed instructions are included. It is set at max boost when shipped. I've been rebuilding turbos for over 18 years, this modification will NOT affect the reliability of your turbo.  I'd be happy  to answer ANY questions you may have.