For length to diameter ratios of less than 12.5 Polysius also equips two-support kilns (instead of the typical POLRO® direct drive) with a girth gear and pinion drive system - often with self-aligning drive pinion.

Apart from the splined kiln tyre fixture, the two-support kiln can also be equipped with a floating-tyre fixture

Depending on the process-technological requirements, rotary kilns can be equipped with e.g. peripheral tertiary air blowers, which ensure the controlled infeeding of combustion air in a reduction process. Other modifications are also possible; for instance co-rotating burner systems or gas injection systems.