Giant 16+ Propel Advanced SL ISP Clamp Spacer Kit Description: This is the Giant 16+ Propel Advanced SL ISP Clamp Spacer Kit. Integrated seatposts are great, but the only drawback is once it is cut, there's no way to go back. Giant has a solution to add height back to a ISP post on the Propel. Features: up to a total of 25mm of added height available Fits 2016+ Propel ISP models only ISP spacers stack in between the seat mast and seat clamp to achieve additional seat height