Full Speed Ahead Full Speed Ahead SL-K SB20 Carbon Seatpost - 27.2 x 400mm BLK/Gray Model-Flite Bullitt In racing KX30 is often

In racing KX30 is often used as the “in between” klister on top of KX20

Shimano XT FC-M8120-1 / Hollowtech 2 / 32T

Compatible with virtually all single-speed and multi-speed chains* including SRAM Flattop and SRAM T-Type

This is what Johannes Høsflot Klæbo says about the Speedmax 3D:

Full Speed Ahead Full Speed Ahead SL-K SB20 Carbon Seatpost - 27.2 x 400mm BLK/Gray Model-Flite Bullitt In racing KX30 is oftenFull Speed Ahead (Full Speed Ahead ) SL K SB20 Carbon Seatpost 27. 2 x 400mm Black Gray. Features a UD carbon shaft with a bonded alloy head thats lighter and stiffer than ever. UD Carbon shaft with bonded SBS 2 bolt alloy head 6061 T6 alloy and carbon fiber 3K weave tubular construction UD Carbon finish Crhromoly steel hardware TECH SPECS Length 400 Color Black Weight 235 Diameter 27. 2 Material Carbon Defined Color Black Clamp Style Standard Rails