Based on this product's specifications, here are some alternatives and similar models
airRoxy pipe reducer 120–125 mm model 02-230 by airRoxy
Summary description:
airRoxy pipe reducer model 02-230 is a ventilation/ducting accessory that adapts a 125 mm connection to 120 mm. Manufactured by airRoxy, this reducer provides a secure mechanical transition between two pipe diameters for ventilation systems, exhausts or air distribution. Suitable for installation in residential or light commercial HVAC and ducting applications where a slight diameter change is required.