I did not design any of these models I just put them together and made print profiles! this is a collection of 3 airless items. A airless basketball, hockey puck, and bouncy ball. all of witch I have tested and do word. the basketball and hockeypuck should be printed in FLEXITOUGH filament designed to bounce and be durable. but I did remix the hockey puck so that it would be more durable and lighter.