Based on this product's specifications, here are some alternatives and similar models
Flush mechanism Nicol 1V01S (single-button water flush control) by Nicol
Summary description:
Nicol 1V01S is a single-button water flush mechanism designed for toilet cisterns. Manufactured by Nicol, this flush valve assembly provides controlled water release for effective bowl clearing. Suitable for replacement or installation in compatible cisterns, it supports standard plumbing connections and is used in residential and commercial bathrooms where a reliable flush control is required.