Model 309P with arms has an 18" seat height suitable for older students.The sturdy polypropylene seats and backs fold so that chairs can be nested and/or stacked for greater space conservation.Durable steel frame is protected from scratches and dings by a scratchresistant gray metal finish.306GB ganging brackets are compatible with this model and will ease setup and keep your rows in order.No assembly required.Stacks/nests up to 15 high.Weight capacity is 300 lbs.Greenguard Certified for Children and Schools.