gray balloon seat sisselSISSEL gray ball seat 65 cm The ball seat should be used for regular, short sessions of approximately 2 hours. The SISSEL ball seat is ideal for office and home office use; its unstable nature provides excellent core training and spinal support. The cover is 100% polyester and is machine washable at 30C. The zipper of the SISSEL ball seat is invisible, covered by the carrying strap to prevent damage to your clothes and floor. The seat comes with the