Rev9Power Rev9_WG-010; RS-Series Wastegate For 50mm V Band Flange Product Details 50MM V BAND RS-SERIES WASTEGATE (universal) "- Includes 1 x 7psi spring, 1 x 10 psi spring , 1 x 12 psi spring (can be combined up to 29 psi) - Dual port. accurate boost - Ultra durable diagram (diaphram) - Comes with all the hardware (bolts, gasket etc) - Accurate boost pressure - High quality appearance - Simple one step process for removing or installing different wastegate springs This wastegate is 5" inches tall. 7 psi spring : outer diameter : 36.5mm / length : 93mm ( inside wastegate ) 10 psi spring : outer diameter : 49mm / length : 90 mm ( extra spring ) 12 psi spring : outer diameter : 59mm / length : 121mm ( extra spring) Example: You can use the 7 or 10 psi spring alone or combine them up together for 21psi. By using all three springs together, will get you up to 29 psi max.