Based on this product's specifications, here are some alternatives and similar models
Expansion Vessel for Domestic Hot Water Reflex DD 18 L (model 7308300)
Summary description:
Reflex DD 18 L expansion vessel designed for domestic hot water systems. This sealed hydraulic accumulator with 18-litre nominal volume helps absorb pressure fluctuations, protects piping and appliances, and maintains system stability. Suitable for installation in hot water circuits, domestic boiler systems and indirect water heaters where an 18 L expansion capacity is required.