The Dogma F8/F10 Flat Back style aero seatpost is fastened from the rear of the seat tube. A frame specific wedge is used to create an ideal fit to the seatpost, and that wedge is pressed against the post via 2 small internal hex screws, sometimes referred to as grub screws. The fastening of these screws requires a torque wrench (4Nm max), and the screws themselves are pretty small. Hence it is not uncommon to misplace, lose or damage one if the user isn't careful. We offer the F8 and F10 wedge and screws as a single replacement system, but if all you need are the screws, we sell those individually here. Remember, this is an individual screw, so if you need more than one, enter the quantity you wish to purchase.