bought parents some sick lightweight trekking poles for anniversary because they're getting old and some lady at REI told me if you use them properly they will take up to 50% of the weight off your knees, correct posture/breathing, help balance, etc. Parents nicely say they are just fine without them in an attempt to pretend to be not old.
alas...i've got trekking poles that have barely been touched.
paid 140 for each pair.
these are they:
http://www.rei.com/product/756152
make me some sort of reasonable offer for one or both.
will accept payment on FTP or Paypal
