Office Chair Piston Cap / Chair Mat Deflector

My office chair's plastic mat has carpet underneath. When my chair rolls off of it, the mat has a tendency to bend up a bit. When I roll back, the mat sometimes hits the chair piston rather than passing under it.

This end cap introduces a slope that will deflect the raised chair mat and direct it under the piston.

STL produced for 44mm (diameter) chair pistons. F3D file provided to easily roll your own for different diameters.