Im selling my Redshift dual position seatpost (27.2mm x 350mm). It's intended for use with Aerobars or Triathlon bars, and it shifts the seat forwards about 2 inches into a super aggressive position. You can really feel the muscles shift, and you're putting down more power. Then you can slide it back to a more relaxed upright position. You can shift the seat forwards and backwards hands free by grabbing it with your thighs and pulling it fwd/back. I bought this to keep up with my riding group, but have since moved on and reverted back to my squishy suspension seat post.
I used the seatpost for about 200 miles, it looks brand new. We are located in Dublin CA.
This sells new on Amazon currently for $250 ($275 with tax), save yourself $75.