Alera Elusion II Series Suspension Mesh Mid-Back Synchro Seat Slide Chair, Supports 275 lb, 16.34" to 20.35" Seat, Black Breathable mesh seat and back provide improved air circulation. Synchro-tilt mechanism smoothly reclines the chair's back and slightly lifts the seat's front. Seat slide adjustment enables the proper seat depth. Height and width adjustable arms for comfortable positioning. Ergonomically designed frame supports proper sitting posture. Ratcheting chair back offers quick and easy height adjustments.