These knobs are perfectly designed and beautifully cut which adds an easiness in your daily working. The knobs have a smooth finish for added comfort as the nozzles rotate complete 360 degree.Multi Flame Sabaf Italian Burners | 1 Big Lotus and 2 Medium Lotus Burner Outlined With Premium Finish Glass Top, it offers a rust resistance texture while delivering long lasting performance. The Toughened glass comes with 5 years warranty too.Warranty: a. 2 Years from date of Purchase on Micro switch, Spark Plug, Generator, Jets.(No warranty on Sabaf Lotus/Enameled Black burners for discoloration, Denting, Deformation & chipping or peeling of enameled black coating) b. 5 Years from date of Purchase on Glass, Valves.Cast iron pan support with Matt enameling helps the container to remain stable on the gas stove. It can steadily hold pans or pots of various sizes for uniform heating.