Waterproof and breathable Isotex 10000 stretch polyester fabric. Breathability rating 10 000g/m2/24 hours. Conforms to EN343:... Waterproof and breathable Isotex 10000 stretch polyester fabric. Breathability rating 10 000g/m2/24 hours. Conforms to EN343:3.3. Hardwearing stretch ripstop fabric for added durability. Reach Technology—Underarm gusset for maximum range of movement. Technical waterproof zips.