The first model, for stoves, has a base diameter of 16 cm and an entry tube diameter of 12 cm. It’s 23 cm high.
It’s perfectly compatible and usable with stoves with oval flue outlet, simply compressing the basis of reduction; this can be easily done by dealer or installer applying moderate pressure on the basis.
The second model, for fireplaces, has a base diameter of 20 cm and an entry tube diameter of 15 cm. It’s 23 cm high.
Stove reduction 16 x 12: RDZS16
Stove reduction 20 x 15: RDZS20