4mm OD X 2.5mm ID Poly Hose Ether Black - PUET04/025N-100 Based tube has a greater durability to water and high humidity environments. • PUET air line tubing is made from 95A shore durometer, ether-based polyurethane and is an excellent choice for compressed air systems. • Kink & abrasion resistant. • Resistant to chemicals, water, fuel & oil. • Outstanding flexibility & memory. Vacuum rating 28" Hg. • Safety Factor of 3 to 1.