TW/THW waya jẹ ohun ti o lagbara tabi idalẹnu, adaorin idẹ rirọ ti annealed pẹlu Polyvinylchloride (PVC).
TW waya dúró fun a thermoplastic, omi sooro waya.
Waya THW tun jẹ thermoplastic, okun waya ti ko ni omi, ṣugbọn o jẹ sooro ooru, tọka nipasẹ H ni orukọ.