Hytrel® 3D4000FL BK513 1.75mm is a 40D TPU

Hytrel is now discontinued by DuPont, but Coex, the contract manufacturer of Hytrel, has been able to rebrand it under CoexFlex.  With CoexFlex, you will receive the same quality filament, made from the same resins and manufacturer as DuPont Hytrel.