... .Performance: anti-knock of abrasion 1.massage balande disc , pvc balance disc , balance board , twist board ,seat cushion ,massage mat2.material: phthalate ... provide "CE" and 'ROHS" certification11.it is used to exercise balance or massage , especiallly suit for yoga exercieser usage: 1. the ... against the floor , then stand on the smooth side --- exercise balance 2. seat on the spikes--massage. massage ...