Pebax^® is a thermoplastic elastomer made up of block copolymers consisting of a sequence of polyamide and polyether segments. The pebax^® grades of the 33 series are composed of polyamide 12 segments (PA12) and polytetramethylene glycol segments (PTMG), leading to a very low material density when compared to the other thermoplastic elastomers, and independently from the grade rigidity.