This is EVABarrier tubing with an 8mm OD (5/16 inch) and is compatible with Duotight and many other push in type fittings.
This tubing is sold by the foot so if you need 3 feet enter 3 in for the quantity.
Please note: Canada Post is now on strike so I will be shipping your package via alternative carriers such as UPS, Canpar or FedEx. The rates are similar enough that you can checkout with Canada Post as the shipping option. If there are any major discrepancies, I'll reach out to let you know prior to shipping. Hopefully this will be resolved quickly. Feel free to reach out with any questions or if you want a shipping quote before placing your order.