The CadoMotus ST is M2 high speed steel (63/64HRC), not bimetal. This means the blade is under less tension than a bimetal blade, and is super straight - straighter out-of-the-box than a Maple and without the fragility of PM steel offered by other brands.
Just 1.1mm thick and rockered at 12 meters, the CadoMotus ST is available in 15 / 15.5 / 16 / 16.5 / 17 / 17.5 / 18 inch.