The global toilet seat market is expected to hit $5.36 billion by 2021, according to a new report.

High-tech and “smart toilets” from Japan are expected to be a major part of revenue, as well as an increase in demand for toilet seat assistive devices and customized, germ-resistant toilet seats, according to the Technavio report.

Assistive devices and raised toilet seats are expected to be a popular option for seniors over age 60 or for those with disabilities. Customized toilets that are germ-resistant are likely be be most in demand from consumers with high incomes.

Toto and Kohler are among companies that have introduced antimicrobial agents within intelligent toilet systems. Other vendors studied in the report included Pressalit.