... strengthened Oxyen Cannula. 2. certificate,CE ,ISO13485 3. anti-crush tube,non-toxic PVC,medical grade ... flexible. nasal oxygen tube helping breathing oxygen1.Made of non-toxic PVC,medical grade ,tubing color ... 5mm/6mm for your choice, anti-crush 3.Different length available,with 2 connectors to match ... oxide gas6.flare or non flare tips7.different types of tips for your choice8.owing to the keelson ...