I use these on my rotary instead of the J109 igniters they work well in that environment, auto dwell etc. These produce greater spark across the rev range out to 9000 rpm with Bosch HIE coils. The lack of any brand new J109 igniters being available so you have to use second hand ones made me switch to these.
They are a direct substitute for the Bosch BIM024 - which is currently unobtanium.