The thomson seat collar qr thomson is famous for their strong reliable and lightweight stems and seatposts the new thomson seat collar qr uses a carbon seat post friendly design with a spherical boltwasher and barrel nut which allows float on both sides of the slit giving better clamping force this seat collar is available in black and silver and the seat collar comes in a variety of sizes thomson seat collar qr features weight 26 28g sizes 286mm 298mm 318mm 349mm 364mm