What are the norms of children's play equipment?

Today's children's play equipment commodity variety, adults with children to playground or park play, many people want to play to relax, then what olympic trampoline equipment most adults and children expect it? From the safety, playability, fees are reasonable to distinguish these three norms.
1. safe
Whether adults or parents with children to take the recreational equipment, the first thing we think is the most important is safe, old age disrepair, rusty children's play equipment, any adult will not play, Let the children to take such a risk.
2. Playability.
Children's play equipment If you can not be rich appearance, attractive way to attract tourists to play, it can not be regarded as a kind of expected goods. We think about to know a kind of recreational equipment if adults and children to see no hobby to play, or play a few times no longer play the hobby so that this device is not expected.