Black Mountain Products professional grade exercise balance disc is made of heavy-duty material for home or gym use. Each balance disc has massage spikes for comfort and maximum grip. With each balance disc a hand pump is included for easy inflation. Wobble discs help improve balance, coordination, flexibility, and core strength. Designed with a 13inch diameter base, each stability disc has ample room for all types of exercises. Perfect tool for flexible classroom seating. All Black Mountain Products comes with a manufactures warranty.