Pres Air Trol TinyTrol 3PDT 3 F Air Switch (MTK211A) sgsinstruments and SPDT relationship gives this and SPDT relationship gives this timer its practical value because timing components need to match the original switching style and electrical role closely if the final repair is going to feel right A kit like this is useful because it restores key structural and visible light components together while still focusing on the plastic assembly parts rather than a fully expanded lighting system package The PresAir Trol TinyTrol 3PDT 3 function air switch is designed for compatible pneumatic control systems that require a more complex switching arrangement in a compact package Compact design for compatible control systems