NON-SLIP SURFACE- Non-slip stripes and frosted surface increase the friction between the stability ball and the user's skin and the ground, thus making the touch more delicate and the anti-slip effect better STRONGER WEIGHT CAPACITY- support up to 330 pounds in weight; the birthing ball prevents a sudden blast; gradual air release mechanism ensures safety; an ideal tool for assisting pregnant women throughout the labor and delivery process SAFETY AND COMFORT- The exercise ball is crafted from PVC material; meticulously manufactured to be free from harmful heavy metals such as Pb, Cd, Hg, and 10 other heavy metals; safe for pregnant women and children MULTI-SCENARIO USE- Not only can it be used as a pregnancy ball to ease maternity pains, it can also work on core muscles and balance; replace traditional office chairs to adjust sitting posture and relieve back pains EASY INFLATION- Trideer exercise ball comes with a quick inflation pump (45/55/65cm equipped with a hand pump; 75/85cm equipped with a foot pump), 2 air stoppers, and detailed instructions; available in 5 sizes to meet all your needs.