What is the difference between Flywheel diodes surge suppressors and Bidirectional peak limiting diodes surge suppressors.

The Flywheel diode surge suppressor is used to limit or remove the surges generated by the coil. Flywheel diode
removes or limits the surge generated by the coil at the time of opening. With this surge suppressor the drop-out
time of coil increases up to 6- 10 times from the standard drop-out time of the coil.

The Bidirectional peak limiting diode surge suppressor provides the protection by limiting the transient voltage up
to 2Uc maximum. With this surge suppressor the opening time of coil remain as standard.