For those of you that just need one Pair!! 

This listing is 1 Pair of trippers 1 on & 1 off These fit Most Intermatic Models Including T101, T102, T103, T104, T102-20 And T104-20 also for WH40 , T1900, T200, C8800, R8800, and T8800 series controls. 

I can email you the list of Dayton compatibility's, or ask me  for a specific clock.