Run a smooth after-school program by having plenty of these heavy-duty plastic stack chairs around rambunctious kids who tend to be tough on seating. These classroom chairs are comfortable with an air-vented back and waterfall seat edge to put students at ease while learning. The 16" seat height is ideal for 3rd - 7th Grade students. These school stack chairs are built to last with a dual-braced frame that can hold up to 661 pounds. School maintenance workers can appreciate student chairs that can stack for floor upkeep, these student desk chairs stack up to 15 chairs high. We consider this student stack chair to be the premier stack chair - essential for every school and classroom setting.