Coming Soon...the SaVeTaO, the Solar Vacuum Tube Oven: a big diameter SK-TF that makes baking, cooking and autoclaving practical and viable, the ultimate PerSiST (Personal Solar Survival Tube) that will outlast the last drop of conventional fuel, so long as the Sun still Shines! The SaVeTaO has a Outer Diameter/Inner Diameter dimension of 120mm/100mm, a good close to 4 inches diameter opening, that comfortably allows access to a full hand with great ease vis-a-vis the mere OD/ID of just 58mm/47mm of the current SK-TF. Watch this space for further exciting developments of the SaVeTaO!