Based on this product's specifications, here are some alternatives and similar models
TECE reducing tee PPSU 25 x 20 x 20 mm, model 8711009
Summary description:
Reducing tee by TECE in PPSU material with dimensions 25 x 20 x 20 mm (model 8711009). Designed for piping systems to join and reduce pipe diameter at a branch point. Suitable for potable water and heating installations where PPSU fittings are required for chemical and temperature resistance. Used in distribution, repair and new installations to connect pipes of differing diameters.