Durable Anti-Burst PVC For safety during pregnancy, we've designed the ball using durable PVC. Not only is it free from phthalates and harmful chemicals, but it has an anti-burst design to slowly deflate if punctured. | Grippy Anti-Slip Lines Worried that the exercise ball will roll away from underneath you? With its anti-slip lines, it's safe to use on smooth flooring. What's more, it provides excellent grip when sitting, lying, or leaning on it. | Pump & Tape Included Inflating the ball to the correct capacity is easy using the pump and tape measure included. For best results, inflate it to 80% of its recommended size and leave it for 24 hours before finishing inflation. |