As of 7/2015 per call to Penn, this wrench only comes with the reel when purchased and is not currently available to order.
You might be able to get one from Penn until their supply runs out:
Penn Fishing Tackle - Parts Customer Service
Monday thru Friday
8:00 A.M. - 5:30 P.M. EST
Phone: (800) 892-5444
Per a recent update, these will get put onto the stocking roster as a 168 TRQ40NLD2 wrench (Former temp# 168-FTHLD2)
We will update when they become available.