Buyers must verify that products comply with international plumbing standards such as cUPC (North America), CE (Europe), or WRAS (UK) to ensure legal sale and installation. Key technical benchmarks include a pressure range of 0.02MPa to 1.6MPa, a life cycle rating of at least 200,000 flush cycles, and anti-siphon functionality to prevent backflow contamination of the clean water supply. Always request salt spray test reports for any metal components (like flush levers) to ensure they won't rust in humid bathroom environments.