Hi. I have for sale a used alloy seatstay removed off a Trek Powerfly LT 7 Plus 2019 (Slate paint scheme). Fits 27,5" wheels. No cracks or dents. Has signs of usage (scratches, paint chips). It fit all Powerfly FS and LT 2017-2019 (don't know if it fits newer). I don't know if it can replace a carbon seatstay. If You are not sure if it fits Your frame just send me a message.