Ergonomically designed, the Kore™ Wobble Chair transforms the conventional boring seat into a playground for your child's imagination. The innovative Kore™ Wobble Chair encourages active sitting and allows one's knees, hips and back to find comfortable and ever-changing positions. Dimensions: 11" diameter seat, 13.75" diameter base, 12" height. Made of durable and recyclable HDPE #2 plastic. Max load weight of 275 lbs. For ages 3-5 or height of 40" -43" .• Homework, reading, drawing, eating and video or board games are no longer sedentary activities.• Ideal for children of all ages, sizes and heights.• Provides an outlet for all high-energy children.• Perfect design for special needs students with ADD, ADHD, and autism. The Kore™ Wobble Chair has proven to increase secondary focus in the classroom.• Patented anti-roll safety ring on base prevents tip-overs and falls.• Gentle-rounded, stable base moves with child and rests naturally upright.• Patented textured design on seat and base to prevent slips; no rubberized bottoms because it holds dirt that causes scratches and scuffles to school floors.• Friction grips to easily assemble or disassemble; also saves storage space when not in use.