Based on this product's specifications, here are some alternatives and similar models
Expansion vessel Reflex N 8, 4 bar / 70°C, grey
Summary description:
Reflex N 8 expansion vessel designed for heating and hot-water systems with a maximum precharge of 4 bar and temperature rating up to 70°C. Manufactured by Reflex, model N 8 serves to compensate for fluid volume changes, maintain system pressure and protect components from overpressure. Suitable for residential and light commercial installations where a compact grey expansion vessel is required.