ETT chairs are recommended for the following environments: industry, education, laboratory, clean room, static control, healthcare and office. Each chair within this series features a different base to meet varied environmental and budget demands. - Contoured waterfall seats and generous backrests with lumbar supports are standard. Select options like seats, backrests, armrests, casters and glides. Performance packages are generally for high-tech (static control and/or clean room) applications. With foot ring