All cores must come with their TSN as this unit has an ultimate life of 9,600 hours. Any cores received without this information will be treated as BER and charged as such. Also, per the latest CMM, the part number must be clearly and completely shown on the unit otherwise we will be forced to issue BER billing. Finally, also per the CMM, electrical defects cannot be repaired so any cores received, that have electrically failed, will automatically be deemed to be BER and charged as such.