The Dual Solenoid Boost Controller R (DSBC Spec R) has four programmable boost settings or various levels of boost. This unit features a built-in boost gauge, peak boost display, four different boost settings, boost warning, scramble boost, and a boost limiter safety feature to prevent over-boosting. The DSBC Spec R uses a dual solenoid design for maximum boost response, capable of handling boost up to 2.5 bar (36 psi). The DSBC Spec R is 1/4 Din size and is campatible with internal actuators and external waste-gates. As an entry-level electronic boost controller, the Dual Solenoid Boost Controller S (DSBC Spec S) offers the same functionality as its counterpart DSBC Spec R. The difference between the DSBC Spec R and Spec S is the solenoid design - Spec R uses a "dual solenoid" while the Spec S utilizes a " single solenoid" design.