I’ve just looked again how it is presented here on Amazon and I must add this caution to my review below and emphasize - safe way for one to have fun! One!Happin’s 1st caution in “Use Instructions” in their manual - “Do not allow more than one person inside… - …can result in serious injuries.”As displayed here on Amazon, there are images of pairs of boys and girls with looks of delight in the trampoline together having a wonderful time! In my opinion, there is not enough room in the 55” trampoline (42” mat space) for two children their sizes to be jumping in it at the same time!My online query of trampoline use by children cautioned against children using trampolines, but if doing so, no more than one at a time!My 79 year old common sense doesn’t allow more than one using the trampoline. Others who purchase it may be as certain. But, even when cautions are in print, the expression - “A picture is worth a thousand words” comes to mind.As eager as children are to have fun and share in that experience and as eager as parents are for their children to have as much fun as possible, there will be the tendency of letting in more than one child. It does not need to be suggested in this Amazon display.My original review follows, with no change other than to note our Grand Girl’s added fun is her “butt drop”, where she stands in the center and drops on her butt - and bounces! She has fallen enough on our hardwood floors, which was never fun, to now knowing where she can enjoy falling and chooses to do so in her Happin.Our 19 month old Grand Girl really enjoys this Happin trampoline. This 951 month old Grand Pa (79+ years) is very satisfied with it and how much fun it provides her. I wish I had gotten it sooner for her. Amazon notes it is for ages 1 to 6. The box notes for ages 3 to 6. No need to wait till 3.My motive for getting it was for her to improve her balance, so as to fall less, as she walks and runs. I had made available to her months ago a mesh sided play pen, in which she learned how to first stand and walk, with no injury from falling. It was a great on-her-feet beginning.I am thankful that Amazon makes available a large selection of trampolines to choose from. The mesh enclosure on this Happin, attached on the bottom to just the jumping surface and held away from the poles, springs and base, was a necessary choice for me, based on how I saw her fall in her mesh sided play pen. Her falls on the trampoline, are not injurious, actually part of the fun.She's been using it for 3 days, learning quickly how to make it an enjoyable jumping experience. Her tendency at first was to grab ahold of the top of the mesh between the poles, as a support while jumping. But, would then also hang on it. She responded nicely to being told it was not made to support weight, just there to hold her from falling out. She could hang onto the poles we told her and she did at first, having something nice to grab ahold of.As she learned to keep her balance while jumping, she no longer had a desire to hold on, now using the mesh to protect her when falling. She also understands she can use the trampoline only while an adult is present and friends have to wait their turn.Online research cautions children using trampolines because of reported injuries. I understand how that can happen on larger trampolines where there is room to run about. The jumping surface on this trampoline within the mesh is just a diameter of 42 inches, inviting jumping, but not enough room for running. The manual includes good advice to assure continued safe use.I used to do all our home maintenance and vehicle service, so recognize quality parts. This Happin is well made, sturdy enough to last, yet light enough to easily move. I was impressed with how carefully it was packaged, how all the parts were protected. As a precaution for out-gassing fumes from the materials - though I didn’t smell any, I opened everything and laid it out during the night on our patio.Assembly was easy, with clear instructions in the manual. Everything fit nicely together with my Grand Girl helping. She handled the parts, including hooking the 36 springs onto the pad for me to stretch to the frame. I’m not using the basketball hoop attached to the trampoline, thinking that as too much of a distraction. I’ll set that up elsewhere.We have it set up in our living room, with a total diameter width being 55 inches. It’s so see through, it doesn’t look that big. It’s easy to collapse to move into other rooms, or out of the way awhile in the garage, or set up outside. Thank you Happin for being available at Amazon, for me to compare with other types. Grand Pa Tom