After each cam or cam kit are the letters Ex, O/R or BL. Their meanings are as follows:
Ex - Exchange camshaft - you need to send your standard camshaft to Piper for reprofiling.
O/R - Outright sale - The cam you will receive has been reprofiled from a standard cam - you do not need to send in your old cam.
BL - Blank - The new cam is machined from either a new casting or a steel billet, so it is brand new.