This timer is designed for use with electric control line stunt model aircraft. It is unique in that it has the ability to monitor the electric motor rpm accurately and use this information as a governor system to keep the revs constant.
It will work with the vast majority of inexpensive ESC`s that do not have a governor mode. If you want to use the timer with an ESC that does have a governor mode that is not suited to C/L stunt, then make sure their governor mode is disabled and also that the SLow or Ultra Slow Start is disabled.
More information available in full instruction manual.