Based on this product's specifications, here are some alternatives and similar models
Reducer fitting SiGMA-Li R3225, PP plastic, 32×25 mm
Summary description:
Reducer fitting SiGMA-Li R3225 made of PP (polypropylene) for plumbing and drainage systems. Concentric/step-down connector for joining 32 mm to 25 mm pipes, providing a secure transition between pipe diameters. Suitable for potable water, wastewater and general domestic installations where reliable plastic pipe connections are required.