The model 910 Gas Chromatograph is the only commercially available dual column oven GC. It is similar to the 910, except that two smaller column ovens are substituted for the larger 910 column oven. Both column ovens are independently temperature programmable from ambient to 400°C, with unlimited ramps and holds, plus fast cool down. Each column oven can accommodate a 4-inch diameter column coil, capillary or packed. Almost all column manufacturers now supply columns in this size. The dual ovens can be used to accomplish user-customized separations. The dual ovens can also be used to double sample throughput for "two GCs in one" cost and space savings (with the addition of a second on-column injection port).