Based on this product's specifications, here are some alternatives and similar models
Unidelta transitional fitting PE female threaded 50 mm x 6/4" (601650)
Summary description:
Transitional PE fitting by Unidelta, female threaded connection sized 50 mm to 6/4" (model 601650). Designed to join polyethylene pipes to threaded components, providing a reliable mechanical and sealed transition. Suitable for water supply and irrigation systems where a PE-to-thread adapter is required. Practical for installation and repair of pipeline connections.