... , PVC plays not so excellently in material functions, but cheaper.2), generally, how long can people stay in the water ball?a). 15-20 ... change the air inside the ball at least every 30 minutes3), HOW DO YOU GET INSIDE OF THOSE BALLS?We have a zipper!4), HOW DO I BLOW ... . .......soon you'll be" water walking" in no time!6), NIGHTIME WATER FUN INSIDE THE "LOVEBALL"We use a long safety rope ...